Which Noble gas will Arsenic try to resemble when it becomes an ION?

Krypton

Explanation:

When arsenic forms an ion, it will try to resemble the structure of krypton. Most atoms always try to mimic the structure of the noble gases because this confers a very stable configuration on them.

Arsenic is an element with five electrons in its outermost shell. It will require just 3 more electrons to attain an octet.

This will make its structure resemble the noble krypton configuration.

The noble gases exists in uncombined form and they do not readily react with other elements.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.