CHEM 219 Exam #2 questions with answers
The atomic radii of zirconium (Zr) and hafnium (Hf) are nearly the same despite the fact
that hafnium has 32 more protons and electrons. Which of the following bests explains this
phenomenon? - **🔰 VERIFIED ANSWERS🔰 ✔✔Hafnium contains electrons in the 4f
orbitals. These 4f electrons do not effectively shield the higher nuclear charge and thus Zeff
is higher than might be otherwise expected.
Which of the following is true concerning successive ionizations of an atom and its ions? -
**🔰 VERIFIED ANSWERS🔰 ✔✔Each successive ionization requires increasing amounts
of energy
The energy of a photon equals its Planck's constant (h) multiplied by the speed of light(c)
and then divided by the wavelength. E = hc/λ. If microwaves are changed to x-rays, what
effect does this have on the energy of the photon - **🔰 VERIFIED ANSWERS🔰 ✔✔The
energy of the photon increases
Photons are shone on a piece of metal and one electron is ejected for each absorbed photon.
What happens when the wavelength of light is decreased? - **🔰 VERIFIED ANSWERS🔰
✔✔The ejected electrons would have greater kinetic energy
What type of light on the electromagnetic spectrum has the highest energy per photon?
X-ray
visible light
microwaves
Gamma waves - **🔰 VERIFIED ANSWERS🔰 ✔✔Gamma waves
, Energy of a photon is ______ proportional to frequency, and _______ proportional to
wavelength - **🔰 VERIFIED ANSWERS🔰 ✔✔directly, inversely
What is observed when a noble gas is heated and the emitted light shone through a prism? -
**🔰 VERIFIED ANSWERS🔰 ✔✔individual lines of varying colors
Heating a noble gas promotes its electrons to excited energy states, which then relax to emit
discrete wavelengths of light. When shone through a prism, this results in individual lines
of varying colors.
Bohr Model - **🔰 VERIFIED ANSWERS🔰 ✔✔model of the atom in which electrons
move rapidly around the nucleus in paths called orbits
Electromagnetic Energy - **🔰 VERIFIED ANSWERS🔰 ✔✔a form of energy that travels
through space in the form of waves
Quantum Theory - **🔰 VERIFIED ANSWERS🔰 ✔✔describes mathematically the wave
properties of electrons and other very small particles
Periodic Properties - **🔰 VERIFIED ANSWERS🔰 ✔✔properties whose values can be
predicted based on the element's position on the periodic table
Which periodic trend quantifies the amount of energy required to remove an electron from
a neutral, gaseous atom? - **🔰 VERIFIED ANSWERS🔰 ✔✔Ionization energy is the
amount of energy required to remove an electron from a neutral, gaseous atom
atomic radius trend - **🔰 VERIFIED ANSWERS🔰 ✔✔The atomic radius increases as you
move down the periodic table and to the left. Tantalum is the furthest to the right of this list
and nearer the top and it would be expected to have the smallest atomic radius
The atomic radii of zirconium (Zr) and hafnium (Hf) are nearly the same despite the fact
that hafnium has 32 more protons and electrons. Which of the following bests explains this
phenomenon? - **🔰 VERIFIED ANSWERS🔰 ✔✔Hafnium contains electrons in the 4f
orbitals. These 4f electrons do not effectively shield the higher nuclear charge and thus Zeff
is higher than might be otherwise expected.
Which of the following is true concerning successive ionizations of an atom and its ions? -
**🔰 VERIFIED ANSWERS🔰 ✔✔Each successive ionization requires increasing amounts
of energy
The energy of a photon equals its Planck's constant (h) multiplied by the speed of light(c)
and then divided by the wavelength. E = hc/λ. If microwaves are changed to x-rays, what
effect does this have on the energy of the photon - **🔰 VERIFIED ANSWERS🔰 ✔✔The
energy of the photon increases
Photons are shone on a piece of metal and one electron is ejected for each absorbed photon.
What happens when the wavelength of light is decreased? - **🔰 VERIFIED ANSWERS🔰
✔✔The ejected electrons would have greater kinetic energy
What type of light on the electromagnetic spectrum has the highest energy per photon?
X-ray
visible light
microwaves
Gamma waves - **🔰 VERIFIED ANSWERS🔰 ✔✔Gamma waves
, Energy of a photon is ______ proportional to frequency, and _______ proportional to
wavelength - **🔰 VERIFIED ANSWERS🔰 ✔✔directly, inversely
What is observed when a noble gas is heated and the emitted light shone through a prism? -
**🔰 VERIFIED ANSWERS🔰 ✔✔individual lines of varying colors
Heating a noble gas promotes its electrons to excited energy states, which then relax to emit
discrete wavelengths of light. When shone through a prism, this results in individual lines
of varying colors.
Bohr Model - **🔰 VERIFIED ANSWERS🔰 ✔✔model of the atom in which electrons
move rapidly around the nucleus in paths called orbits
Electromagnetic Energy - **🔰 VERIFIED ANSWERS🔰 ✔✔a form of energy that travels
through space in the form of waves
Quantum Theory - **🔰 VERIFIED ANSWERS🔰 ✔✔describes mathematically the wave
properties of electrons and other very small particles
Periodic Properties - **🔰 VERIFIED ANSWERS🔰 ✔✔properties whose values can be
predicted based on the element's position on the periodic table
Which periodic trend quantifies the amount of energy required to remove an electron from
a neutral, gaseous atom? - **🔰 VERIFIED ANSWERS🔰 ✔✔Ionization energy is the
amount of energy required to remove an electron from a neutral, gaseous atom
atomic radius trend - **🔰 VERIFIED ANSWERS🔰 ✔✔The atomic radius increases as you
move down the periodic table and to the left. Tantalum is the furthest to the right of this list
and nearer the top and it would be expected to have the smallest atomic radius
