The answer is atoms good luck
<u><em>Answer:</em></u>
<u><em>Explanation:</em></u>
Phosphate ion has covalent bond. As we known , covalent bond is formed by sharing of electrons between two atoms. As in this case, P form three single covalent bond with three oxygen atoms and one double covalent bond with one oxygen . The formal charges is -3.
While He is present in mono atomic form
NaI have ionic bond which is formed by donating electrons from one atom and other accept.
Ag is present independently with no other atom.
After the first 2 min the 20 g are only 10g, (1 half-life)
after other 2 more min 5g (2 half-lives)
after other 2 more min 2.5 g (3 half-lives)
after 2 more 1.25 g (4 haf lifes)