Test 3
Why are the atomic masses listed in the periodic table not whole numbers?
The atomic masses are average atomic masses
Which of these photons has the greatest energy?
Ultraviolet
Each spectral line in a spectrum represents
a specific frequency of light emitted by an element
Any material that is made up of only one type of atom is classified as
an element.
Atoms are best described using
conceptual models.
When an atom is excited, its
electrons are boosted to higher energy levels
Excitation is the process whereby
electrons are boosted to higher energy levels in an atom
The most abundant element in the universe is
hydrogen
What is known about atoms is that they are
mostly empty space
The mass number of an element refers to the number of
nucleons in its nucleus
How can a hydrogen atom , which has only one electron , have so many spectral lines?
one electron can be boosted to many different energy levels
In an electrically neutral atom, the number of protons in the nucleus is balanced by an equal number of
orbital electrons
A quantum of light is called a
photon
The atomic number of an element matches the number of
protons in the nucleus of an atom.
The shell model of the atom views electrons as occupying
shells
The origin of the elements is
the stars
The lanthanides are much like a group of elements because
they share similar properties
Electrons in the outermost shells of atoms are called
valence electrons
In the relationship E ∼ ƒ, E stands for energy, and ƒ stands for
wave frequency, as defined for sound, radio, and light waves
Which of the following is a quantum number?
1
How many groups are there in the periodic table?
Eighteen
Helium, He, is a nonmetallic gas and the second element in the periodic table. Rather than being placed adjacent to hydrogen, H, however, helium is placed on the far right of the table. Why?
Helium is most similar to other group 18 elements
Which of the following particles are electrically neutral?
Neutron
Which has less energy per photon?
Red light