Answer:
plaster is important because of the many uses you can make out of plaster
The formula we can use here is the Plancks equation:
E = h c / ʎ
where h is Plancks constant = 6.626 × 10-34 m2 kg / s, c
is speed of light = 3 x 10^8 m/s and ʎ is wavelength = 656.1 x 10^-9 m
Therefore E is:
E = (6.626 × 10-34 m2 kg / s)
* (3 x 10^8 m/s) / 656.1 x 10^-9 m
<span>E = 3.03 x 10^-19 J</span>
According to the equation, the ratio of the reactant Cu and product CuO is 2:2, thus 1:1. Therefore to produce 2.44 mol CuO, 2.44 mol Cu is required. The molecular weight of Cu is 64. So the mass of Cu that is required to produce 2.44mol CuO is 2.44mol * 64 g/mol = 156.16 g.
It can change the phase of matter. The rest of the answers are chemical changes but increasing temperature indices a physical change which is only found in the first choice
