When candle burns:
a. its size decreases.
b. there is melting of wax.
c. flame and soot can be seen.
d. melted wax also solidies.
From the observations, which one of the following is correct?
1. a is a physical change and others are chemical changes.
2. c is a chemical change and others are physical changes.
3. a & b are physical changes and c & d are chemical changes.
4. a, b and c are physical changes.