What’s the answer to this?

Answer : The balanced chemical reaction will be:

Explanation :

Balanced chemical reaction : It is defined as the reaction in which the number of atoms of individual elements present on reactant side must be equal to the product side.

When solid calcium metal reacts with aqueous aluminum nitrate then it gives aqueous calcium nitrate and solid aluminium.

The balanced chemical reaction will be:

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.

i believe it is-

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