Chapter 5 Electrons in Atoms
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Circle the letter of the term that completes the sentence correctly. A quantum of energy is the amount of energy required to a. place an electron in an energy level. b. maintain an electron in its present energy level. c. move an electron from its present energy level to a higher one.
C
Bohr
Electrons move in circular orbits at fixed distances from the nucleus.
When electrons occupy orbitals of equal energy, one electron enters each orbital until all the orbitals contain one electron with the same spin direction.
Hund's rule
What does de Broglie's equation predict about the behavior of particles?
It predicts that all moving objects have wavelike behavior.
Does the Heisenberg uncertainty principle apply to cars and airplanes?
No, it applies only to small particles.
An atomic orbital may describe at most two electrons.
Pauli exclusion principle
What is the difference between the previous models of the atom and the modern quantum mechanical model?
Previous models described the motion of electrons in the same was as the motion of large objects. The quantum mechanical model uses mathematical equations to describe the behavior of electrons.
__________ describes the motion of very small particles, such as subatomic particles.
Quantum mechanics
What type of radiation has the lowest frequency? The highest frequency?
Radio waves have the lowest frequency. Gamma rays have the highest frequency.
The letter __________ is used to denote a spherical orbital.
S
In an electron configuration, what does the sum of the superscripts equal?
The sum equals the number of electrons in the atom.
In an electron configuration, what does a superscript stand for?
The superscript stands for the number of electrons occupying a given sublevel.
The wave's height from zero to the crest.
amplitude
Passing the light emitted by an element through a prism gives the __________ of the element.
atomic emission spectrum
A(n) __________ is often thought of as a region of space in which there is a high probability of finding an electron.
atomic orbital
Electron configurations can be written by using the __________, the Pauli exclusion principle, and Hund's rule.
aufbau principle
The product of wavelength and frequency always equals a(n) __________ the speed of light.
constant (c)
The ways in which electron are arranged into orbitals around the nuclei of atoms are called __________.
electron configurations
What are the fixed energies of electrons called?
energy levels
Is the following sentence true or false? Every element in the periodic table follows the aufbau principle.
false
Bohr proposed that an electron is found only in specific circular paths, or __________, around the nucleus.
orbits
What did Albert Einstein call the quanta of light energy?
photons
What is the term that is used to label the energy levels of electrons?
principal quantum numbers (𝑛)
Describing light as __________ of energy that behave as particles helps to explain the photoelectric effect.
quanta
The __________ model describes the energy an electron can have and the probability of finding the electron in various locations around the nucleus of an atom.
quantum mechanical
When sunlight passes through a prism, the different wavelengths separate into a(n) __________ of colors.
spectrum
Filled energy sublevels are more __________ than partially filled sublevels.
stable
Orbitals, which are found in __________, have different shapes, depending on the energy of the electrons they contain.
sublevels
Which atomic orbital is of higher energy, a 4𝑓 or a 5𝑝 orbital?
4𝑓
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Is the following sentence true or false? Quantum mechanics describes the motions of subatomic particles and atoms as waves.
true
Is the following sentence true or false? The quantum mechanical model of the atoms estimated the probability of finding an electron in a certain position.
true
Is the following sentence true or false? The wavelength and frequency of light are inversely proportional.
true
According to the Heisenberg uncertainty principle, it is impossible to know exactly both the __________ and the __________ of a particle at the same time.
velocity, position
What is the formula for the maximum number of electrons that can occupy a principal energy level? Use 𝑛 for the principal quantum number.
2𝑛²
__________ describes the motion of large bodies.
Classical mechanics
Rutherford
Most of an atom's mass is concentrated in the small, positively charged nucleus. The electrons are in motion in the space around the nucleus.
Thomson
The atom is a sphere of positive electrical charge with electrons embedded in the sphere.
Dalton
The atom is a tiny, indestructible particle with no internal structure.
What happens when an electric current is passed through the gas or vapor of an element?
The atoms absorb energy, which causes them to emit light.
Electrons occupy orbitals of lowest energy first.
aufbau principle
When atoms absorb energy, their electrons move to higher __________.
energy levels
Is the following sentence true or false? The electrons in an atom can exist between energy levels.
false
Is the following sentence true or false? The emission spectrum of an element can be the same as the emission spectrum of another element.
false
In general, the higher the electron is on the energy ladder, the __________ it is from the nucleus.
farther
Half-filled levels are not as stable as __________ levels, but are more stable than other configurations.
filled
The number of wave cycles to pass a given point per unit of time.
frequency
When an electron drops to a lower energy level, it emits light that has a __________ directly proportional to the energy change of the electron.
frequency
What is the lowest possible energy of an electron called?
ground state
The units of frequency are usually per second. The SI unit of cycles per second is called a(n) __________.
hertz (Hz)
Only electrons moving from __________ to __________ energy levels lose energy and emit light.
higher, lower
The distance between two crests.
wavelength