Energy values were quantized. Get unlimited access to over 88,000 lessons. According to Bohr's model only certain orbits were allowed which means only certain energies are possible. What is the frequency, v, of the spectral line produced? They emit energy in the form of light (photons). Figure 22.8 Niels Bohr, Danish physicist, used the planetary model of the atom to explain the atomic spectrum and size of the hydrogen atom. The Loan class in Listing 10.210.210.2 does not implement Serializable. Wikimedia Commons. According to Bohr's postulates, electrons tend to have circular orbit movements around the nucleus at specified energy levels. Atomic and molecular spectra are quantized, with hydrogen spectrum wavelengths given by the formula. The main points of Bohr's atomic model include the quantization of orbital angular momentum of electrons orbiting the charged, stationary nucleus of an atom due to Coulomb attraction, which results in the quantization of energy levels of electrons. What is the frequency, v, (in s-1) of the spectral line produced? Adding energy to an electron will cause it to get excited and move out to a higher energy level. Learn about Niels Bohr's atomic model and compare it to Rutherford's model. If ninitial> nfinal, then the transition is from a higher energy state (larger-radius orbit) to a lower energy state (smaller-radius orbit), as shown by the dashed arrow in part (a) in Figure \(\PageIndex{3}\) and Eelectron will be a negative value, reflecting the decrease in electron energy. Each element is going to have its own distinct color when its electrons are excited - or its own atomic spectrum. Light that has only a single wavelength is monochromatic and is produced by devices called lasers, which use transitions between two atomic energy levels to produce light in a very narrow . c. Calcu. Quantifying time requires finding an event with an interval that repeats on a regular basis. Figure \(\PageIndex{1}\): The Emission of Light by Hydrogen Atoms. Quantization of energy is a consequence of the Bohr model and can be verified for spectroscopic data. Hydrogen absorption and emission lines in the visible spectrum. Its like a teacher waved a magic wand and did the work for me. Both account for the emission spectrum of hydrogen. ), whereas Bohr's equation can be either negative (the electron is decreasing in energy) or positive (the electron is increasing in energy). Third, electrons fall back down to lower energy levels. While the electron of the atom remains in the ground state, its energy is unchanged. In the Bohr model, what happens to the electron when a hydrogen atom absorbs energy? Bohr's model calculated the following energies for an electron in the shell, n. n n. n. : E (n)=-\dfrac {1} {n^2} \cdot 13.6\,\text {eV} E (n) = n21 13.6eV. The Bohr Atom. According to Bohr, electrons circling the nucleus do not emit energy and spiral into the nucleus. What does Bohr's model of the atom look like? One of the bulbs is emitting a blue light and the other has a bright red glow. The atomic spectrum of hydrogen was explained due to the concept of definite energy levels. The states of atoms would be altered and very different if quantum states could be doubly occupied in an atomic orbital. Order the common kinds of radiation in the electromagnetic spectrum according to their wavelengths or energy. As n increases, the radius of the orbit increases; the electron is farther from the proton, which results in a less stable arrangement with higher potential energy (Figure \(\PageIndex{3a}\)). Hybrid Orbitals & Valence Bond Theory | How to Determine Hybridization. A. His description of atomic structure could satisfy the features found in atomic spectra and was mathematically simple. (Do not simply describe, The Bohr theory explains that an emission spectral line is: A) due to an electron losing energy but keeping the same values of its four quantum numbers. Electromagnetic radiation comes in many forms: heat, light, ultraviolet light and x-rays are just a few. Gov't Unit 3 Lesson 2 - National and State Po, The Canterbury Tales: Prologue Quiz Review, Middle Ages & Canterbury Tales Background Rev, Mathematical Methods in the Physical Sciences, Physics for Scientists and Engineers with Modern Physics. Report your answer with 4 significant digits and in scientific notation. Suppose that you dont know how many Loan objects are there in the file, use EOFException to end the loop. (a) Use the Bohr model to calculate the frequency of an electron in the 178th Bohr orbit of the hydrogen atom. Describe his hydrogen spectra experiment and explain how he used his experimental evidence to add to the understanding of electron configuration? Using these equations, we can express wavelength, \( \lambda \) in terms of photon energy, E, as follows: \[\lambda = \dfrac{h c}{E_{photon}} \nonumber \], \[\lambda = \dfrac{(6.626 \times 10^{34}\; Js)(2.998 \times 10^{8}\; m }{1.635 \times 10^{-18}\; J} \nonumber \], \[\lambda = 1.215 \times 10^{-07}\; m = 121.5\; nm \nonumber \]. In the spectrum of a specific element, there is a line with a wavelength of 656 nm. Bohr was able to advance to the next step and determine features of individual atoms. Neils Bohr proposed that electrons circled the nucleus of an atom in a planetary-like motion. Modified by Joshua Halpern (Howard University). Hint: Regarding the structure of atoms and molecules, their interaction of radiations with the matter has provided more information. 11. lessons in math, English, science, history, and more. If this electron gets excited, it can move up to the second, third or even a higher energy level. A theory based on the principle that matter and energy have the properties of both particles and waves ("wave-particle duality") Bohr suggested that an atomic spectrum is created when the _____ in an atom move between energy levels. In what region of the electromagnetic spectrum would the electromagnetic r, The lines in the emission spectrum of hydrogen result from: a. energy given off in the form of a photon of light when an electron "jumps" from a higher energy state to a lower energy state. Bohr's model of an atom failed to explain the Zeeman Effect (effect of magnetic field on the spectra of atoms). This also serves Our experts can answer your tough homework and study questions. As an example, consider the spectrum of sunlight shown in Figure \(\PageIndex{7}\) Because the sun is very hot, the light it emits is in the form of a continuous emission spectrum. where \(n_1\) and \(n_2\) are positive integers, \(n_2 > n_1\), and \(R_{H}\) the Rydberg constant, has a value of 1.09737 107 m1 and Z is the atomic number. - Definition, Uses, Withdrawal & Addiction, What Is Selenium? Ionization Energy: Periodic Table Trends | What is Ionization Energy? In which region of the spectrum does it lie? Line spectra from all regions of the electromagnetic spectrum are used by astronomers to identify elements present in the atmospheres of stars. All rights reserved. When heated, elements emit light. For a multielectron system, such as argon (Z = 18), one must consider the Pauli exclusion principle. Niels Bohr won a Nobel Prize for the idea that an atom is a small, positively charged nucleus surrounded by orbiting electrons. . When sodium is burned, it produces a yellowish-golden flame. Telecommunications systems, such as cell phones, depend on timing signals that are accurate to within a millionth of a second per day, as are the devices that control the US power grid. In the spectrum of atomic hydrogen, a violet line from the Balmer series is observed at 434 nm. Does not explain why spectra lines split into many lines in a magnetic field 4. Electron orbital energies are quantized in all atoms and molecules. Neils Bohr sought to explain the Balmer series using the new Rutherford model of the atom as a nucleus surrounded by electrons and the new ideas of quantum mechanics. When neon lights are energized with electricity, each element will also produce a different color of light. According to Bohr's model of the atom, orbits closer to the nucleus would require the electrons to have a greater amount of energy, and orbits farther from the nucleus would require the electrons to have a smaller amount of energy. Responses that involved physics concepts that were at Level 8 of the curriculum allowed the Different spectral lines: He found that the four visible spectral lines correlate with the transition from higher energy levels to lower energy levels (n = 2). Figure 1. Buring magnesium is the release of photons emitted from electrons transitioning to lower energy states. Electrons. Find the kinetic energy at which (a) an electron and (b) a neutron would have the same de Broglie wavelength. 7.3: Atomic Emission Spectra and the Bohr Model is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by LibreTexts. corresponds to the level where the energy holding the electron and the nucleus together is zero. Only the Bohr model correctly characterizes the emission spectrum of hydrogen. Legal. Which of the following electron transitions releases the most energy? The discrete amounts of energy that can be absorbed or released by an atom as an electron changes energy levels are called _____. The lowest-energy line is due to a transition from the n = 2 to n = 1 orbit because they are the closest in energy. A line in the Balmer series of hydrogen has a wavelength of 486 nm. d. movement of electrons from lower energy states to h. Which was an assumption Bohr made in his model? C. It transitions to a lower energy orbit. Niels Bohr proposed a model for the hydrogen atom that explained the spectrum of the hydrogen atom. [\Delta E = 2.179 * 10^{-18}(Z)^2((1/n1^2)-(1/n2^2))] a) - 3.405 * 10^{-20}J b) - 1.703 * 10^{-20}J c) + 1.703 * 10^{-20}J d) + 3.405 * 10^{-20}J. c. why electrons travel in circular orbits around the nucleus. It also explains such orbits' nature, which is said to stationary, and the energy associated with each of the electrons. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. For example, when copper is burned, it produces a bluish-greenish flame. How is the cloud model of the atom different from Bohr's model. a. n = 5 to n = 3 b. n = 6 to n = 1 c. n = 4 to n = 3 d. n = 5 to n = 4 e. n = 6 to n = 5, Which statement is true concerning Bohr's model of the atom? . It could not explain the spectra obtained from larger atoms. Bohr's model breaks down . Other families of lines are produced by transitions from excited states with n > 1 to the orbit with n = 1 or to orbits with n 3. In a later lesson, we'll discuss what happens to the electron if too much energy is added. Use the Bohr model to determine the kinetic and potential energies of an electron in an orbit if the electron's energy is E = -10.e, where e is an arbitrary energy unit. The Rydberg equation can be rewritten in terms of the photon energy as follows: \[E_{photon} =R_yZ^{2} \left ( \dfrac{1}{n^{2}_{1}}-\dfrac{1}{n^{2}_{2}} \right ) \label{7.3.2}\]. 167 TATI. What was the difficulty with Bohr's model of the atom? Bohr's atomic model explains the general structure of an atom. He earned a Master of Science in Physics at the University of Texas at Dallas and a Bachelor of Science with a Major in Physics and a Minor in Astrophysics at the University of Minnesota. So the difference in energy (E) between any two orbits or energy levels is given by \( \Delta E=E_{n_{final}}-E_{n_{initial}} \) where nfinal is the final orbit and ninitialis the initialorbit. During the solar eclipse of 1868, the French astronomer Pierre Janssen (18241907) observed a set of lines that did not match those of any known element. You wouldn't want to look directly at that one! Figure 7.3.6: Absorption and Emission Spectra. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. It is due mainly to the allowed orbits of the electrons and the "jumps" of the electron between them: Bohr tells us that the electrons in the Hydrogen atom can only occupy discrete orbits around the nucleus (not at any distance from it but at certain specific, quantized, positions or radial distances each one corresponding to an energetic state of your H atom) where they do not radiate energy. Of course those discovered later could be shown to have been missing from the matrix and hence inferred. Niels Bohr was able to show mathematically that the colored lines in a light spectrum are created by: electrons releasing photons. Bohr proposed an atomic model and explained the stability of an atom. Photoelectric Effect Equation, Discovery & Application | What is the Photoelectric Effect? In all these cases, an electrical discharge excites neutral atoms to a higher energy state, and light is emitted when the atoms decay to the ground state. It also failed to explain the Stark effect (effect of electric field on the spectra of atoms). Related Videos Given: lowest-energy orbit in the Lyman series, Asked for: energy of the lowest-energy Lyman emission and corresponding region of the spectrum. B. Using what you know about the Bohr model and the structure of hydrogen and helium atoms, explain why the line spectra of hydrogen and helium differ. In 1913, a Danish physicist, Niels Bohr (18851962; Nobel Prize in Physics, 1922), proposed a theoretical model for the hydrogen atom that explained its emission spectrum. The Bohr model of hydrogen is the only one that accurately predicts all the electron energies. Using the ground state energy of the electron in the hydrogen atom as -13.60 eV, calculate the longest wave length spectral line of the Balmer series. The energy of the photons is high enough such that their frequency corresponds to the ultraviolet portion of the electromagnetic spectrum. Thus, they can cause physical damage and such photons should be avoided. Bohr's model explains the stability of the atom. Createyouraccount. Because a sample of hydrogen contains a large number of atoms, the intensity of the various lines in a line spectrum depends on the number of atoms in each excited state. Scientists needed a fundamental change in their way of thinking about the electronic structure of atoms to advance beyond the Bohr model. \[ E_{photon-emitted} = |\Delta E_{electron} | \], We can now understand the theoreticalbasis for the emission spectrum of hydrogen (\(\PageIndex{3b}\)); the lines in the visible series of emissions (the Balmer series) correspond to transitions from higher-energy orbits (n > 2) to the second orbit (n = 2). \[ E_{photon} = (2.180 \times 10^{-18}\; J) 1^{2} \left ( \dfrac{1}{1^{2}} - \dfrac{1}{2^{2}} \right ) \nonumber \], \[ E_{photon} = 1.635 \times 10^{-18}\; J \nonumber \]. Wavelength is inversely proportional to frequency as shown by the formula, \( \lambda \nu = c\). Niel Bohr's Atomic Theory states that - an atom is like a planetary model where electrons were situated in discretely energized orbits. copyright 2003-2023 Homework.Study.com. a. A spectral line in the absorption spectrum of a molecule occurs at 500 nm. Does it support or disprove the model? 2. shows a physical visualization of a simple Bohr model for the hydrogen atom. 2. The orbit closest to the nucleus represented the ground state of the atom and was most stable; orbits farther away were higher-energy excited states. succeed. Spectral lines produced from the radiant energy emitted from excited atoms are thought to be due to the movements of electrons: 1.from lower to higher energy levels 2.from higher to lower energy levels 3.in their orbitals 4.out of the nucleus, Explain the formation of line spectrum in the Balmer series of hydrogen atom. Write a program that reads the Loan objects from the file and displays the total loan amount. It only explained the atomic emission spectrum of hydrogen. The atomic number of hydrogen is 1, so Z=1. 2) What do you mean by saying that the energy of an electron is quantized? Bohr did what no one had been able to do before. (The minus sign is a notation to indicate that the electron is being attracted to the nucleus.) {/eq}. What is the quantum theory? To achieve the accuracy required for modern purposes, physicists have turned to the atom. There are several postulates that summarize what the Bohr atomic model is. Which statement below does NOT follow the Bohr Model? The steps to draw the Bohr model diagram for a multielectron system such as argon include the following: The Bohr atomic model of the atom includes the notion that electrons orbit a fixed nucleus with quantized orbital angular momentum and consequently transition between discretized energy states discontinuously, emitting or absorbing electromagnetic radiation. According to Bohr's model, what happens to the electron when a hydrogen atom absorbs a photon of light of sufficient energy? At the temperature in the gas discharge tube, more atoms are in the n = 3 than the n 4 levels. Bohr used a mixture of ____ to study electronic spectrums. This means that each electron can occupy only unfilled quantum states in an atom. Kinetic energy: Potential energy: Using the Rydberg Equation of the Bohr model of the hydrogen atom, for the transaction of an electron from energy level n = 7 to n = 3, find i) the change in energy. Hence it does not become unstable. Where, relative to the nucleus, is the ground state of a hydrogen atom? (a) n = 10 to n = 15 (b) n = 6 to n = 7 (c) n = 1 to n = 2 (d) n = 8 to n = 3. Use the Rydberg equation to calculate the value of n for the higher energy Bohr orbit involved in the emission of this light. 4.72 In order for hydrogen atoms to give off continuous spectra, what would have to be true? We're going to start off this lesson by focusing on just the hydrogen atom because it's a simple atom with a very simple electronic structure. Hydrogen Bohr Model. In what region of the electromagnetic spectrum is this line observed? Bohr's model of hydrogen is based on the nonclassical assumption that electrons travel in specific shells, or orbits, around the nucleus. In what region of the electromagnetic spectrum does it occur? Calculate the atomic mass of gallium. Clues here: . How does the Bohr theory account for the observed phenomenon of the emission of discrete wavelengths of light by excited atoms? Imagine it is a holiday, and you are outside at night enjoying a beautiful display of fireworks. Atoms of individual elements emit light at only specific wavelengths, producing a line spectrum rather than the continuous spectrum of all wavelengths produced by a hot object. Types of Chemical Bonds | What is a Chemical Bond? Calculate the energy dif. Using the Bohr formula for the radius of an electron orbit, estimate the average distance from the nucleus for an electron in the innermost (n = 1) orbit of a copper atom (Z = 29). Using the Bohr atomic model, explain to a 10-year old how spectral emission and absorption lines are created and why spectral lines for different chemical elements are unique. Types of Chemical Bonds: Ionic vs Covalent | Examples of Chemical Bonds, Atomic Number & Mass Number | How to Find the Atomic Mass Number, Interaction Between Light & Matter | Facts, Ways & Relationship, Atomic Spectrum | Absorption, Emission & History, Balancing Chemical Equations | Overview, Chemical Reactions & Steps, Dimensional Analysis Practice: Calculations & Conversions, Transition Metals vs. Main Group Elements | List, Properties & Differences, Significant Figures & Scientific Notation | Overview, Rules & Examples. Enter your answer with 4 significant digits. His model was based on the line spectra of the hydrogen atom. They can't stay excited forever! In the Bohr model, is light emitted or absorbed when an electron moves from a higher-energy orbit to a lower-energy orbit? Regardless, the energy of the emitted photon corresponds to the change in energy of the electron. As n decreases, the energy holding the electron and the nucleus together becomes increasingly negative, the radius of the orbit shrinks and more energy is needed to ionize the atom. A. They are exploding in all kinds of bright colors: red, green . Suppose a sample of hydrogen gas is excited to the n=5 level. This is where the idea of electron configurations and quantum numbers began. The Balmer series is the series of emission lines corresponding to an electron in a hydrogen atom transitioning from n 3 to the n = 2 state. Did not explain spectra of other elements 2. How is the cloud model of the atom different from Bohr's model? He developed the quantum mechanical model. In the case of sodium, the most intense emission lines are at 589 nm, which produces an intense yellow light. b) Planck's quantum theory c) Both a and b d) Neither a nor b. In fact, the term 'neon' light is just referring to the red lights. Alpha particles are helium nuclei. Which of the following transitions in the Bohr atom corresponds to the emission of energy? Bohr became one of Denmark's most famous and acclaimed people and a central figure in 20th century physics. The Bohr model is a simple atomic model proposed by Danish physicist Niels Bohr in 1913 to describe the structure of an atom. Using the Bohr model, determine the energy (in joules) of the photon produced when an electron in a Li^{2+} ion moves from the orbit with n = 2 to the orbit with n = 1. The current standard used to calibrate clocks is the cesium atom. b. This is called its atomic spectrum. Bohr's model can explain the line spectrum of the hydrogen atom. Example \(\PageIndex{1}\): The Hydrogen Lyman Series. It does not account for sublevels (s,p,d,f), orbitals or elecrtron spin. From what state did the electron originate? Bohr's theory successfully explains the atomic spectrum of hydrogen. Discuss briefly the difference between an orbit (as described by Bohr for hydrogen) and an orbital (as described by the more modern, wave mechanical picture of the atom). Approximately how much energy would be required to remove this innermost e. What is the wavelength (in nm) of the line in the spectrum of the hydrogen atom that arises from the transition of the electron from the Bohr orbit with n = 3 to the orbit with n = 1. c. Neutrons are negatively charged. Even interpretation of the spectrum of the hydrogen atom represented a challenge. Ernest Rutherford's atomic model was an scientific advance in terms of understanding the nucleus, however it did not explain the electrons very well, as a charged particle The number of rings in the Bohr model of any element is determined by what? Can the electron occupy any space between the orbits? These findings were so significant that the idea of the atom changed completely. 2. The Bohr model is often referred to as what? Niels Henrik David Bohr (Danish: [nels po]; 7 October 1885 - 18 November 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922. By comparing these lines with the spectra of elements measured on Earth, we now know that the sun contains large amounts of hydrogen, iron, and carbon, along with smaller amounts of other elements. Rydberg's equation always results in a positive value (which is good since photon energies are always positive quantities!! Consider the Bohr model for the hydrogen atom. The electron in a hydrogen atom travels around the nucleus in a circular orbit. Explain what photons are and be able to calculate their energies given either their frequency or wavelength . What was once thought of as an almost random distribution of electrons became the idea that electrons only have specific locations where they can be found. Express the axis in units of electron-Volts (eV). The Swedish physicist Johannes Rydberg (18541919) subsequently restated and expanded Balmers result in the Rydberg equation: \[ \dfrac{1}{\lambda }=R_{H}Z^{2}\left( \dfrac{1}{n^{2}_{1}}-\dfrac{1}{n^{2}_{2}} \right ) \label{7.3.1}\]. That's what causes different colors of fireworks! In the case of mercury, most of the emission lines are below 450 nm, which produces a blue light. This little electron is located in the lowest energy level, called the ground state, meaning that it has the lowest energy possible. 3. Decay to a lower-energy state emits radiation. In this model n = corresponds to the level where the energy holding the electron and the nucleus together is zero. In the Bohr model of the atom, what is the term for fixed distances from the nucleus of an atom where electrons may be found? When the electron moves from one allowed orbit to . (A), (B), (D) are correct (the total energy of an electron is quantized; electrons orbit in definite energy levels; radiation can only occur when electron jumps from one orbit to another orbit). Finally, energy is released from the atom in the form of a photon. The theory explains the hydrogen spectrum and the spectra of one electron species such as \ (\rm {He . where is the wavelength of the emitted EM radiation and R is the Rydberg constant, which has the value. Explore how to draw the Bohr model of hydrogen and argon, given their electron shells. C) due to an interaction between electrons in. It is the strongest atomic emission line from the sun and drives the chemistry of the upper atmosphere of all the planets, producing ions by stripping electrons from atoms and molecules. Bohr assumed that electrons orbit the nucleus at certain discrete, or quantized, radii, each with an associated energy. In contemporary applications, electron transitions are used in timekeeping that needs to be exact. Niels Bohr, Danish physicist, used the planetary model of the atom to explain the atomic spectrum and size of the hydrogen atom. Bohr's atomic model is also commonly known as the ____ model. His measurements were recorded incorrectly. A model of the atom which explained the atomic emission spectrum of hydrogen was proposed by _____. The orbit with n = 1 is the lowest lying and most tightly bound. (e) More than one of these might. Bohr's model was a complete failure and could not provide insights for further development in atomic theory. One is the notion that electrons exhibit classical circular motion about a nucleus due to the Coulomb attraction between charges. Second, electrons move out to higher energy levels. Because a hydrogen atom with its one electron in this orbit has the lowest possible energy, this is the ground state (the most stable arrangement of electrons for an element or a compound) for a hydrogen atom. I would definitely recommend Study.com to my colleagues. Unfortunately, scientists had not yet developed any theoretical justification for an equation of this form. If Bohr's model predicted the observed wavelengths so well, why did we ultimately have to revise it drastically? 4.66 Explain how the Bohr model of the atom accounts for the existence of atomic line spectra. An emission spectrum gives one of the lines in the Balmer series of the hydrogen atom at 410 nm. Superimposed on it, however, is a series of dark lines due primarily to the absorption of specific frequencies of light by cooler atoms in the outer atmosphere of the sun. B. n=2 to n=5 (2) Indicate which of the following electron transitions would be expected to emit any wavelength of, When comparing the Bohr model to the quantum model, which of the following statements are true? Supercooled cesium atoms are placed in a vacuum chamber and bombarded with microwaves whose frequencies are carefully controlled. If the emitted photon has a wavelength of 434 nm, determine the transition of electron that occurs. Using the model, consider the series of lines that is produced when the electron makes a transistion from higher energy levels into, In the Bohr model of the hydrogen atom, discrete radii and energy states result when an electron circles the atom in an integer number of: a. de Broglie wavelengths b. wave frequencies c. quantum numbers d. diffraction patterns. (Do not simply describe how the lines are produced experimentally. In order to receive full credit, explain the justification for each step. Electrons cannot exist at the spaces in between the Bohr orbits. When the frequency is exactly right, the atoms absorb enough energy to undergo an electronic transition to a higher-energy state. How do you determine the energy of an electron with n = 8 in a hydrogen atom using the Bohr model? Planetary model. I hope this lesson shed some light on what those little electrons are responsible for! Do we still use the Bohr model? So, who discovered this? Calculate and plot (Energy vs. n) the first fiv. In this state the radius of the orbit is also infinite. The electron in a hydrogen atom travels around the nucleus in a circular orbit. B. How did Niels Bohr change the model of the atom? Bohr's model breaks down when applied to multi-electron atoms. Bohr proposed that electrons move around the nucleus in specific circular orbits. When the atom absorbs one or more quanta of energy, the electron moves from the ground state orbit to an excited state orbit that is further away. He suggested that they were due to the presence of a new element, which he named helium, from the Greek helios, meaning sun. Helium was finally discovered in uranium ores on Earth in 1895.