The products lie on the right hand side of the equation. So, in this case, they are:
S and O₂
The answer is C.
For question two, you figure out the amount of sodium atoms on the left and right side and the amount of oxygen atoms on the left and right side
So for two it would be 4, 1, 2
For question four, you figure out the amount of atoms on each side
So for four it would be 1, 2, 1, 2
Answer is "A".
Explanation;
Physical changes mean an arrangement of particles of a given substance without producing new substance but changes in physical form of the substance.
<em>Example :</em> vaporization of water ( water goes its gaseous phase from liquid form).
Chemical changes mean an arrangement of particles while forming new substance.
<em>Example : </em>heating of CaCO₃. (In this process CaO and CO₂ are formed).
In this problem, the volume of water has decreased. Hence, it can be said that this is an example of physical changes due to not forming of new substance.