What is the relationship between the atomic numbers and ionic radii of the elements in the group 2a?

what is the relationship between atomic numbers and first ionization energies? (2a group)

why do these relationships exist? propose an explanation for each of these relationships. (2a group)

are these relationships consistent with the periodic trends that you have been studying? (2a group)

As the atomic number increases, the ionic radius increases.
As the atomic number increases, the first ionization energy decreases.

These trends both exists because as we proceed down the group, the size of the atom increases due to addition of an electron shell. The increased number of electrons increase the shielding effect, meaning the ion is not held together as tightly, increasing its size, and the outer most electrons are not pulled towards the nucleus as strongly, making it easier to remove them.

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom

Ithink the answer is c