As you move from left to right across the second period of the periodic table, the a. ionization energy increases. b. atomic radii increase. c. electron affinity decreases. d. atomic mass decreases.

A would be correct. Have a nice day. :)

ionization energy increases.

Explanation:

As move from left to right

a) the atomic number increases but the number of shells remain the same hence the size of elements decreases (except noble gas).

b) Due to decrease in size the effective nuclear charge increases and this causes increase in ionization energy.

c) the electron affinity also increases on moving left to right

d) with increase in atomic number the atomic mass also increases.

So correct answer is

ionization energy increases.

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."