The speed at which electromagnetic radiation moves through a vacuum is called the___.

In the following sets of elements, indicate which element has the smallest atomic size.

b. $\mathrm{Na}, \mathrm{Si}, \mathrm{S}$

In the following sets of elements, indicate which element has the smallest atomic size.

a. $\mathrm{Na}, \mathrm{K}, \mathrm{Rb}$

Arrange the following sets of elements in order of increasing atomic size.

c. $\mathrm{Pb}, \mathrm{Ba}, \mathrm{Cs}, \mathrm{At}$

Arrange the following sets of elements in order of increasing atomic size.

b. $\mathrm{Rn}, \mathrm{He}, \mathrm{Xe}, \mathrm{Kr}$

Arrange the following sets of elements in order of increasing atomic size.

a. $\mathrm{Sn}, \mathrm{Xe}, \mathrm{Rb}, \mathrm{Sr}$

Differentiate among the terms energy level, sub-level, and orbital.

In the following sets of elements, which element would be expected to have the highest ionization energy?

d. $\mathrm{Mg}, \mathrm{Si}, \mathrm{S}$

In the following sets of elements, which element would be expected to have the highest ionization energy?

c. $\mathrm{I}, \mathrm{Br}, \mathrm{Cl}$

In the following sets of elements, which element would be expected to have the highest ionization energy?

b. $\mathrm{Ba}, \mathrm{Sr}, \mathrm{Ca}$

In the following sets of elements, which element would be expected to have the highest ionization energy?

a. $\mathrm{Cs}, \mathrm{K}, \mathrm{Li}$

In the following groups, which element is least reactive?

d. Group 6

What term is used to describe the fact that electromagnetic radiation can be thought of as either a continuous wave or as a stream of individual packets of energy?

In the following groups, which element is least reactive?

c. Group 2