Formation of ionic bond is affected by​

Ionization energy, electronegativity, and lattice energy are the factors that influence the formation of ionic bonds of 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.

1.solid

2.carbon dioxide

3.helium