Chapter 9 - Electron in Atoms and the Periodic Table
How many electrons can the d subshell hold?
10 electrons
How many electron can the f subshell hold?
14 electrons.
What order do electrons fill orbitals?
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s
How many electrons can the s subshell hold?
2 electrons
How many electrons can the p subshell hold?
6 electrons
What is a photon?
A photon is a particle of light. A photon has a specific wavelength. Violet light (shorter wavelength) carries more energy per photon than red light (longer wavelength).
What is a quantum number?
A quantum number is an integer that specifies the energy of an orbital. The higher the quantum number "n", the greater the distance between the electron and the nucleus and the higher its energy. The energy of each orbit increases with increasing value of "n", but the levels become more closely spaced as "n" increases.
What is a subshell?
A subshell in quantum-mechanics, specifies the shape of the orbital and is represented by different letters (s, p, d, f). The subshell of the orbital specifies its shape. Each subshell letter corresponds to a different shape.
What is a white-light spectrum?
A white-light spectrum is continuous, with some radiation emitted at every wavelength. The emission spectrum of an individual element includes only certain specific wavelengths.
Choose the element with the higher ionization energy from each pair. a) Mg or Sr b) In or Te c) C or P d) F or S
A) Mg - Ionization energy decreases as you move down B) Te - Ionization energy increases as you move right C) Can't Tell D) F
Choose the element with the higher ionization energy from each pair. a) Mg or P b) As or Sb c) N or Si d) O or Cl
A) P - Ionization energy increase as you move right B) As - Ionization energy decreases as you move down C) Can't Tell D) Can't Tell
Choose the larger atom in each pair. a) Pb or Po b) Rb or Na c) Sn or Bi d) F or Se
A) Pb - it is further left on the periodic table B) Rb - it further down on the periodic table C) Can't Tell D) Se - It is further down and more to the left
Write the electron configuration for each element. a) Al - It has 13 electrons b) Br - It has 35 electrons c) Sr - It has 38 electrons
Al - 1s^2 2s^2 2p^6 3s^2 3p^1 or [Ne]3s^23p^1 Br - 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^5 or [Ar]4s^2 3d^10 4p^5 Sr - 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 or [Kr]5s^2
Write the electron configuration for each ion. (Hint: To determine the number of electrons to include in the electron configuration of an ion, add or subtract electrons as needed to account for the charge of the ion.) Subtract 1 electron for each unit of positive charge. Add 1 electron for each unit of negative charge. a) Al^3+ - It has 13 - 3 electrons - 10 b) Cl- - It has 17 = 1 electron - 18 c) O^2- - It has 8 + 2 electrons - 10
Al^3+ = 1s^2 2s^2 2p^6 Cl- = 1s^2 2s^2 2p^6 3s^2 3p^6 O^2- = 1s^2 2s^2 2p^6
Are Alkaline Earth Metals (Group 2) reactive metals?
Alkaline earth metals (group 2), with an outer electron configuration of ns^2, also tend to be reactive metals, losing their ns^2 electrons to form 2+ cations. In their reactions, they tend to lose two electrons forming 2+ ions and attaining a noble gas configuration.
Are Alkaline metals (Group 1) reactive metals?
Alkaline metals (group 1) are among the most reactive metals since their outer electron configuration (ns^1) is 1 electron beyond a noble gas configuration. If they react to lose the ns^1 electron, they attain a noble gas configuration.
What is an electron configuration?
An electron configuration is a compact way to specify the occupation of quantum-mechanical orbitals by electrons. It illustrates the occupation of orbitals by electrons for a particular atom. Lower-energy levels fill before higher-energy orbitals.
What is an electron spin?
An electron spin is a fundamental property of all electrons that causes them to have magnetic fields associated with them. The spin of an electron can either be oriented up (+1/2) or down (-1/2). The direction of the atom (pointing up or pointing down) represents the electron spin. All electrons have spin.
What is an emission spectrum?
An emission spectrum is a spectrum associated with the emission of electromagnetic radiation by elements or compounds. The white-light spectrum is continuous, meaning that the the light intensity is uninterrupted or smooth across the entire visible range - there is some radiation at all wavelengths, with no gaps. The emission spectrum of hydrogen, helium, and neon are not continuous. They consist of bright spots or lines at specific wavelengths with complete darkness in between.
What is an excited state?
An excited state is an unstable state for an atom or a molecule in which energy has been absorbed but not remitted, raising an electron from the ground state into a higher energy level. Because of their higher energy, excited state are unstable, and the electron will usually fall (or relax) back to a lower-energy orbital. In the process, the electrons emits energy often the form of light. The energy difference between the two orbitals involved in the transition determines the wavelength of the emitted light (the greater the energy difference, the shorter the wavelength)
What is an orbital diagram?
An orbital diagram is an electron configuration in which electrons are represented as arrows in boxes corresponding to orbitals or a particular atom. Orbitals can be represented as geometric shapes. The box represents the 1s orbital, and the arrows within the box represents the electron in the 1s orbital. Orbitals can hold no more than two electrons each.
What is an orbital?
An orbital is the region around the nucleus of an atom where the electron is most likely to be found.
Write an orbital diagram for argon (Ar) The atomic number of Ar is 18.
Ar <> <> <><><> <> <><><> 1s 2s 2p 3s 3p
Write an electron configuration for arsenic based on its position in the periodic table.
As = [Ar]4s^2 3d^10 4p^3
What is the symbol, the electron configuration and orbital diagram of Beryllium?
Beryllium Symbol - Be (4) Electron Configuration - 1s^2 2s^2 Orbital Diagram - <> <> 1s 2s
What is the symbol, the electron configuration and orbital diagram of Boron?
Boron Symbol - B (5) Electron Configuration - 1s^2 2s^2 2p^1 Orbital Diagram - <> <> < 1s 2s 2p
Which type of electromagnetic radiation has the longest wavelength? a) visible b) ultraviolet c) infrared d) x-ray
C) Infrared
What is the symbol, the electron configuration and orbital diagram of Carbon?
Carbon Symbol - C (6) Electron Configuration - 1s^2 2s^2 2p^2 Orbital Diagram - <> <> << 1s 2s 2p
Write an electron configuration for chlorine and identify the valence electrons and the core electrons. Cl - atomic number 17
Cl = 1s2 2s2 2p6 3s2 3p5 There are two outermost shells = Level 3 = 3s2 3p5 = 7 valence electrons The rest are core electrons: 1s2 2s2 2p6
Write an electronic configuration for chlorine and identify the valence and core electrons. The atomic number for Cl is 17.
Cl = 1s^2 2S^2 2p^6 3s^2 3p^5 Valence Electrons for Cl are n =3. Valence Electrons = 3s^2 3p^5 Core Electrons = 1s^2 2S^2 2p^6
What are core electrons?
Core electrons are the electrons that are not in the outmost principal shell.
What is dot density?
Dot density is when orbitals are represented by dots, where the dot density is proportional to the probability of finding an electron. The dot density for the 1s orbital is greatest near the nucleus and decreases farther away from the nucleus. The electron is more likely to be found close to the nucleus than far away from it.
What is Electromagnetic Radiation?
Electromagnetic Radiation is a type of energy that travels through space at a constant speed of 3.0 X 10^8m/s (186,000 mi/s). The wavelength of electromagnetic radiation determines the amount of energy carried by one of its photons. The shorter the wavelength, the greater the energy of each photon. Electromagnetic Radiation is a form of energy that travels through space at a constant speed of 3.0 X 10^8 m/s and can exhibit wavelike or particle-like properties.
How to electrons exist?
Electrons exist in quantized orbits at specific, fixed energies and specific, fixed distances from the nucleus.
What energy level does do electrons occupy?
Electrons occupy the lowest-energy orbitals available, and only two electrons (with opposing spins) are allowed in each orbital, we can build ground-state electron configuration for the rest of the elements as long as we know the energy ordering of the orbitals. Electrons occupy orbitals so as to minimize the energy of the atom: therefore, lower-energy orbitals fill before higher-energy orbitals.
What is the symbol, the electron configuration and orbital diagram of Fluorine?
Fluorine Symbol - F (9) Electron Configuration - 1s^2 2s^2 2p^5 Orbital Diagram - <> <> <><>< 1s 2s 2p
What is frequency?
Frequency is the number of cycles that pass through a stationary point in one second. Wavelength and frequency are inversely related: the shorter the wavelength, the higher the frequency. The frequency and energy of electromagnetic radiation are inversely related to it wavelength. Example: Blue light has a higher frequency that red light.
Write the electron configuration for Ga (gallium). It has 31 electrons.
Ga - 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^1 Using the noble gas Ar = 1s^2 2s^2 2p^6 3s^2 3p^6 [Ar]4s^2 3d^10 4p^1
Are halogens (group 7) reactive nonmetals?
Halogens (group 7) are the most reactive nonmetals, because of their ns^2np^5 electron configurations. They are only one electron away from a noble gas configuration and tend to react to gain that one electron, forming 1- ions.
Explain the Bohr Model of an atom.
In the Bohr mode of the atom, a single quantum (n) specifies each orbit. The energy of each Bohr orbit, specified by a quantum number n=1, 2,3 is fixed or quantized. Bohr orbits are like steps of a ladder, each at a specific distance from the nucleus and at a specific energy. It is impossible for an electron to exist between orbits in the Bohr model. The Bohr model cannot predict spectra for atoms with more than one electron.
Explain the Quantum-Mechanical model of an atom.
In the quantum-mechanical model, a number and a letter specify an orbital (or orbitals). This model replaced the Bohr model, because it failed to predict the emission spectra of other elements that contained more than one electron. Orbits were replaced with orbitals. The lowest-energy orbital in the quantum-mechanical model is the 1s orbital. Orbitals represent probability maps that show a statistical distribution of where the electron is likely to be found. We cannot describe an electron's exact path.
List the types of electromagnetic radiation in order of increasing energy per photon. a) radio waves b) microwaves c) infrared d) ultraviolet
Increasing Energy Per Photon Radio Waves Microwaves Infrared Ultraviolet
What is Infrared Light?
Infrared light is between visible light and microwaves. The heat we feel when we place a hand near a hot object is infrared light. All warm objects, including human bodies, emit infrared light. Infrared light is invisible to our eyes, but infrared sensors can detect it.
What is ionization energy of an atom?
It is the energy required to remove an electron from the atom in the gaseous state. The ionization of sodium can be represented in the following equation: Na + Ionization Energy -----> Na+ + 1e- As you move right across the periodic table, ionization energy increases. As you move down the periodic table, ionization energy decreases. -------------------> Ionization Energy Increases I I Ionization Energy Decreases (Down) I V
What is the Pauli Exclusion Principle?
It states that orbitals may hold no more than two electrons with opposing spins. A helium atom has two electrons. Electron Configuration: 1s^2 Orbital Diagram: <>1s When two electrons occupy the same orbital, they must have opposing spins. This is know as the Pauli exclusion principle.
What is Hund's Rule?
It states that when filling orbitals of equal energy, electrons fill them singly first,with parallel spins. When orbitals of identical energy are available, these are first occupied singly with parallel spins rather than in pairs. This is known as Hund's rule.
What is light?
Light is a form of electromagnetic radiation. A flash of light generated at the equator can travel around the world in 1/7 of a second.
What is the symbol, the electron configuration and orbital diagram of Lithium?
Lithium Symbol - Li (3) Electron Configuration - 1s^2 2s^1 Orbital Diagram- <> < 1s 2s
Which elements gain/lose electrons in chemical reactions?
Metals tend to lose electrons in chemical reactions. Nonmetals tend to gain electrons in chemical reactions.
Write the electron configuration for Mg (magnesium). It has 12 electrons.
Mg - 1s^2 2s^2 2p^6 3s^2 Using the noble gas core Ne = 1s^2 2s^2 2p^6 Mg - [Ne]3s^2
What are Microwaves?
Microwaves are between infrared light and radio waves. They are used for radar and microwave ovens. Microwaves are efficiently absorbed by water. Therefore microwaves heat substances that contain water such as food, but not items that do not contain water such as a plate.
If the shell n=1, what are the number of subshells and the letters specifying the subshells?
N=1 The number of subshells equals 1. The letters specifying the subshell is s.
If the shell n=2, what are the number of subshells and the letters specifying the subshells?
N=2 The number of subshells equals 2. The letters specifying the subshells are s & p
If the shell n=3, what are the number of subshells and the letters specifying the subshells?
N=3 The number of subshells equals 3. The letters specifying the subshells are s, p, d
If the shell n=4, what are the number of subshells and the letters specifying the subshells.
N=4 The number of subshells equals 4. The letters specifying the subshells are s, p, d, f
What is the symbol, the electron configuration and orbital diagram of Neon?
Neon Symbol - Ne (10) Electron Configuration - 1s^2 2s^2 2p^6 Orbital Diagram - <> <> <><><> 1s 2s 2p
What is the symbol, the electron configuration and orbital diagram of Nitrogen?
Nitrogen Symbol - N (7) Electron Configuration - 1s^2 2s^2 2^p^3 Orbital Diagram - <> <> <<< 1s 2s 2p
What is a quality of a noble gas and alkali metal?
Noble gases are chemically inert. Alkali metals are chemically reactive.
How many valence electrons do noble gases have?
Noble gases contains 8 valence electrons (2 for Helium). They are predicted to be particularly low in energy and therefore stable. Elements with electron configurations close to the noble gases are the most reactive because they can attain noble gas electron configurations by losing or gaining a small number or electrons.
What is the symbol, the electron configuration and orbital diagram of Oxygen?
Oxygen Symbol - O (8) Electron Configuration - 1s^2 2^2 2p^4 Orbital Diagram - <> <> <><< 1s 2s 2p
What is quantum of energy?
Quantum energy is the precise amount of energy released when an electron falls back or relaxes back to a lower energy orbit. The precise amount of energy possessed by a photon; the difference in energy between two atomic orbitals.
What are the different wavelengths on the electromagnetic spectrum from longest to shortest?
Radio Waves - Longest Wavelength Microwaves Infrared Radiation Visible Light Ultraviolet Light (UV Light) X-Rays Gamma Rays - Shortest Wavelength
What are radio waves?
Radio waves are the longest wavelengths. The are used to transmit the signals used by AM and FM radio, cellular telephones, television, and other forms of communication.
Write the electron configuration for S (Sulfur). It has 16 electrons.
S - 1s^2 2s^2 2p^6 3s^2 3^p4 Using the noble gas Ne = 1s^2 2s^2 2p^6 S - [Ne]3s^2 3p^4
Write an electron configuration for selenium and identify the valence electrons and the core electrons. Se = atomic number 34
Se = 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p4 The are two outermost shells = Leve1 4= 4s2 & 4p4 = 6 valence electrons The rest are core electrons: 1s2 2s2 2p6 3s2 3p6 3d10
Write an electron configuration for selenium and identify the valence electrons and the core electrons. The atomic number for Se is 34.
Se = 1s^2 2S^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^4 The valence electrons are those in the outermost shell. The outer most shell of Se is n=4. Valence Electrons - 4s^2 & 4p^4 Core Electrons - 1s^2 2S^2 2p^6 3s^2 3p^6 3d^10
Write an orbital diagram for silicon (Si). The atomic number for Si is 14.
Si <> <> <><><> <> << 1s 2s 2p 3s 3p
Use the periodic table to determine the electron configuration for tin. The atomic number for tin is 50.
Sn = 1s^2 2s^2 2p^6 3s^2 3p^6 3d^10 4s^2 4p^6 4d^10 5s^2 5p^2 Kr = 1s^2 2s^2 2p^6 3s^2 3p^6 3d^10 4s^2 4p^6 Sn = [Kr] 5s^2 4d^10 5p^2
What is the symbol and, the electron configuration of Sodium?
Sodium Symbol - Na (11) Electron Configuration - 1s^2 2s^2 2p^6 3s^1
What is the Bohr model?
The Bohr model is a model form the atom in which electrons travel around the nucleus in circular orbits at specific, fixed distances from the nucleus.
What is the atomic size of and atom?
The atomic size of an atom is determined by the distance between the outermost electrons and the nucleus. As you move right across the periodic table, the atomic size decreases. As you move down the periodic table, the atomic size increases. -------------------------> Atomic Size Decreases I I Atomic Size Increases (down) I V
How are chemical properties of elements largely determined?
The chemical properties of elements are largely determined by the number of valence electrons they contain. The elements withing a column in the periodic table have the same number of valence electrons. They also have similar properties.
What is the electromagnetic spectrum?
The electromagnetic spectrum is the entire range of electromagnetic radiation. Electromagnetic radiation ranges in wavelength from 10^16 m (gamma rays) to 10^6 m (radio waves). Visible light composes only a small portion of that range.
What are the first two columns of the left side of the periodic table?
The first two columns on the left side of the periodic table are the s block with outer electron configuration of ns^1 (first column) and ns^2 (second column).
What is the ground state?
The ground state is the lowest energy state. The state of an atom or molecule in which the electrons occupy the lowest possible energy orbitals available. All of the atoms of each element have one ground state and many excited states.
What is the highest principal quantum number?
The highest principal quantum number (highest n value) is equal to the row number of the element in the periodic table. For any element containing d electrons, the principal quantum number (n value) of the outermost d electrons is equal to the row number of the element minus 1.
Where are the lanthanides and actinides located on the periodic table.
The lanthanides and actinides (also called the inner transition metals) are located in the f block.
What is the principle quantum number?
The principle quantum number is a number that indicates the shell that an electron occupies.
What is the principle shell?
The principle shell is the shell indicated by the principal quantum number. The number is the principle quantum number (n) and specifies the principle shell of the orbital. The higher the principal quantum number, the higher the energy of the orbital.
What is the quantum-mechanical model?
The quantum-mechanical model the foundation of modern chemistry, explains how electrons exist in atoms and how they affect the chemical and physical properties of elements.
What are Gamma Rays?
The shortest wavelength on the electromagnetic spectrum. The are the most energetic. The photons of gamma rays are produced by the sun, stars and by certain unstable nuclei on Earth. Excessive human exposure to gamma rays is dangerous because the high energy of gamma ray photons can damage biological molecules.
What are the six columns on the right side of the periodic table?
The six column on the right side of the periodic table are the p block with electron configurations of: ns^2 np^1, ns^2, np^2, ns^2 np^3, ns^2 np^4, ns^2 np^5 (halogens) and ns^2 np^6 (noble gases) The inner electron configuration for any element is the electron configuration of the noble gas that immediately precedes that element in the periodic table. We represent the inner configuration with the symbol for the noble gas in brackets.
Where are the transition metals located on the periodic table?
The transition metals are located in the d block.
List two types of electromagnetic radiation with frequencies higher than visible light.
Ultraviolet Light Gamma Rays X-Rays
What is Ultraviolet Light (UV Light)?
Ultraviolet light is between x-rays and visible light on the electromagnetic spectrum. Most familiar UV light is a component of sunlight that produces sunburns or suntans. Not as energetic as gamma or x-rays, UV light photons still carry enough energy to damage biological molecules. Excessive exposure to ultraviolet light increases the risk of skin cancer and cataracts and causes premature wrinkling of the skin.
What are valence electrons?
Valence electrons are the electrons in the outermost principal she (the principal shell with the highest principal quantum number n). These electrons are held most loosely and are most easily lost or shared. They are involved in chemical bonds. We can determine the outer electrons from the element's position with particular block (s, p, d or f) in the periodic table. We trace the elements between the preceding noble gas and the element of interest, and assign electrons to the appropriate orbitals. The chemical properties of elements are largely determined by the number of valence electrons they contain.
What is Visible Light?
Visible light is between ultraviolet light and infrared light. Visible light photons do not damage biological molecules. The cause molecules in our eyes to rearrange which sends signals to our brains that results in vision.
What is a wavelength?
Wavelength is the distance between adjacent wave crests. For visible light, wavelength determines color. The wavelength of electromagnetic radiation determines the amount of energy carried by one of its photons. The shorter the wavelength, the greater the energy of each proton.
What happens when an atom absorbs energy?
When an atom absorbs energy, an electron is one of the fixed orbits is excited or promoted to an orbit that is farther away from the nucleus and therefore higher in energy. When energy is put into an atom, electrons are excited to higher-energy orbits. In this new configuration, the atom is less stable, and the electron quickly falls back or relaxes to a lower-energy orbit. When an electron in an atom relaxes (or falls) from a higher-energy orbit to a lower-energy orbit, the atom emits light. The energy (and therefore the wavelength) of the emitted light corresponds to the energy difference between the two orbits in the transition. Since these energies are fixed and discrete, the energy (and therefore the wavelength) of the emitted light is fixed and discrete.
What is Noble Gas Core Notation?
When writing electron configurations for elements beyond neon or beyond any other noble gas - the electron configuration of the previous noble gas can be abbreviated by the symbol for the noble gas in brackets. Example - Sodium Na = 1s2 2s2 2p6 3s1 Na = [Ne] 3s1
What are X-Rays?
X-Rays - Next to gamma rays on the electromagnetic spectrum. X-Rays are familar to us due to their medical uses. X-Rays can pass through many substances that block visible light and are therefore used to image internal bones and organs. X-Ray photons carry enough energy to damage biological molecules. Excessive exposure to X-Rays increases cancer risk.
Which wavelength of light has the highest frequency? a) 350 nm b) 500 nm c) 750 nm
a) 350 nm Wavelength and frequency are inversely related. Therefore, the shortest wavelength has the highest frequency.
Which element has the fewest valence electrons? a) B - Boron = 1s^2 2s^2 2p^1 b) Ca - Calcium - 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 c) O - Oxygen = 1s^2 2^2 2p^4 d) K - Potassium - 1s^2 2s^2 2p^6 3s^2 3p^6 4s^1 e) Ga - Gallium = 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^1
a) B - Valence Electrons - n=2 = 3 valence electrons b) Ca - Valence Electrons - n=4 = 2 valence electrons c) O - Valence Electrons - n=2 = 6 valence electrons d) K - Valence Electrons - n=4 = 1 valence electron e) Ga - Valence Electrons - n=4 = 3 valence electrons D - The outermost principal shell for K is n=4, which contains only a single valence electron, 4s^1.
Choose the larger atom in each pair. a) C or O b) Li or K c) C or Al d) Se or I
a) C Carbon atoms are larger than O atoms because as you move right atomic size decreases. b) K Potassium atoms are larger than Li atoms because as you move down atomic size increases. C) Aluminum atoms are larger than C atoms because down increase size and left increases. These effects overall together increase. D) You cannot tell based on periodic properties alone. The effects tend to cancel each other out.
Below is the electron configuration of calcium: Ca = 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 In its reaction, calcium tends to form the Ca^2+ ion. Which electrons are lost upon ionization? a) the 4s electrons b) two of the 3p electrons c) the 3s electrons d) the 1s electrons
a) Calcium loses it 4s electron and attains a noble gas configuration (that of Ar).
Arrange the colors of visible light - green, red and blue - in order of increasing: a) wavelength b) frequency c) energy per photon
a) wavelength Blue - Green - Red (Gamma Rays, Visible Light, Radio Waves) b) frequency Red - Green - Blue (Radio Waves, Visible Light, Gamma Rays) c) energy per photon Red - Green - Blue (Radio Waves, Visible Light, Gamma Rays)
Arrange the three types of electromagnetic radiation - visible light, x-rays and microwaves - in order of increasing: a) wavelength b) frequency c) energy per photon
a) wavelength x-rays, visible light, microwaves b) frequency microwaves, visible light, x-rays c) energy per photon - Energy per photon decreases with increasing wavelength but increases with increasing frequency. microwaves, visible light, x-rays
Yellow light has a longer wavelength than violet light. Therefore: a) Yellow light has more energy per photon than violet light. b) Yellow light has less energy per photon than violet light. c) Both Yellow light and violet light have the same energy per photon.
b) Yellow light has less energy per photon than violet light. Wavelength and energy per photon are inversely related. Since yellow light has a longer wavelength it has less energy per photon than violet light. Wavelength inversely proportional to energy per photon Larger Wavelength has less energy per photon
In one transition, an electron in a hydrogen atom falls from the n=3 level to the n=2 level. In the second transition, an electron in a hydrogen atom falls from the n=2 level to the n=1 level. Compared to the radiation emitted by the first of these transitions, the radiation emitted by the second has: a) a lower frequency b) a smaller energy per photon c) a shorter wavelength d) a longer wavelength
c) A shorter wavelength The higher energy levels are more closely spaced than the lower ones, so the difference in energy between n=2 and n=1 is greater than the difference in energy between n=3 and n=2. The photon emitted when an electron falls from n=2 to n=1 carries more energy, corresponding radiation with a shorter wavelength and higher frequency.
Which pair of elements has the same total number of electrons in p orbitals? a) Na and K b) K and Kr c) P and N d) Ar and Cr
d) Both have 6 electrons in 2p oribitals and 6 electrons in 3p orbitals.
