Answer
a - Chemical property
b - Physical property
c - Physical property
d- Chemical property
Work Step by Step
a - Chemical property as baking soda reacts with vinegar and new chemical substances are produced as the result of this reaction.
b - Physical property: the sentence describes how ice melts at $0^{o}C$, as a result ice changes its physical status from solid to liquid. No chemical reaction occur.
c - Physical property : the sentence describes the color, the physical state, and the hardness of graphite. No chemical reaction occur.
d- Chemical property: in the process of burning of hydrogen in air, hydrogen reacts with the oxygen of the air. So there is a chemical reaction happening between hydrogen and oxygen of the air.
