Among the following, which atom is most likely to form an ion with a charge of 2+? ca al na o

Ca

Explanation:

Calcium atom has two electrons that are loosely attached to its outermost energy level. It easily looses these electrons during reactions than the other three elements ( aluminium,sodium and oxygen).

Ca₍aq₎⇒ Ca²⁺₍aq₎+2e⁻

Calcium ionizes by losing 2 electrons from its outer shell to form an ion with a charge of 2+

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 don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.