<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.
The corrects answer is 259 K
Answer:
the answer would be Halogens
Answer:
it is endothermic change ..........
are present in 
<u>Explanation:</u>
It is known that each mole of an element is composed of avagadro's number of molecules. So if we need to determine, we need to divide the number of molecules with the avagadro's number.
So,

As here
molecules of carbon di oxide is given. So the moles in it will be
No. of moles of carbon dioxide = 
No. of moles =
moles of carbon dioxide.
Thus,
of carbon dioxide are present in
.