<u>Answer:</u>
211.9 J
<u>Explanation:</u>
The molecules of water release heat during the transition of water vapor to liquid water, but the temperature of the water does not change with it.
The amount of heat released can be represented by the formula:

where
= heat energy,
= mass of water and
= latent heat of evaporation.
The latent heat of evaporation for water is
and the mass of the water is
.
The amount of heat released in this process is:
211.9 J
'cause alphe-particle which was +ve charge, get repulsion from the atom, so he deducted that.......
Answer:
4 means there are four molecules of Na₂SO₃.
Explanation:
Molecule:
A molecule is the smaller particle which can exist independently.
It may be monoatomic , diatomic, triatomic etc.
For example,
Hydrogen molecule consist of two atoms H₂
Nitrogen molecule = N₂
It may be combination of atoms of different elements.
HCl, H₂SO₄,Na₂SO₃
HCl = 1 mole of hydrochloric acid or one molecules of hydrochloric acid
H₂SO₄= 1 mole of sulfuric acid or one molecule of sulfuric acid
Na₂SO₃ = 1 mole of sodium sulfite or one molecule of sodium sulfite.
4Na₂SO₃ = 4 mole of sodium sulfite or four molecule of sodium sulfite.
The coefficient before the formula indicate the total number of molecules.