Ratio of the rate of diffusion of Nitrogen(I)oxide to carbon(Iv)oxide​

Calcium chloride +gold(1) oxide—>

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.

Is 9 correct? and can someone me with 10? it’s due tomorrow, you