Answer: option A. 2
Explanation: in the formula Sr3(PO4)2, the 2 behind (PO4) is affecting both P and O4. It means that we have P2 in the formula
Answer:
Alternative Titles: nuclear force, strong interaction, strong nuclear force. Strong force, a fundamental interaction of nature that acts between subatomic particles of matter. The strong force binds quarks together in clusters to make more-familiar subatomic particles, such as protons and neutrons.
Answer:C
Explanation: ice molecules are solid
Answer: The mass of
and
produced are 336.6 g and 183.6 g respectively.
Explanation:
The combustion reaction between propane and oxygen leads to formation of carbon dioxide and water.
Law of Conservation of mass states that the mass will remain constant for a balanced equation. This is carried out when the total number of atoms on reactant side is same as the total number of atoms on the product side. Thus the equation must be balanced.

a) 1 mol of propane produces = 3 moles of
Thus 2.55 mol of propane produces =
mass of 
b) 1 mol of propane produces = 4 moles of
Thus 2.55 mol of propane produces =
mass of
The mass of
and
produced are 336.6 g and 183.6 g respectively.