Which of the elements shown will form ions, what will be the charges of those ions, and why will they have those charges?

the sodium and chlorine are the form of ion

Explanation:

because sodium have tendency to loose electron it become positive ion and chlorine has tendency to gain electron it becomes negative ion

the law of conservation of mass states that in a chemical reaction, the total mass of reactants is equal to the total mass of products. because atoms are only rearranged in a chemical reaction, there must be the same number of sodium atoms and chlorine atoms in both the reactants and products

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.