Which statement describes a physical change?
a.
sodium metal reacts explosively with oxygen.
b.
lead is heated and becomes more viscous.
c.
calcium is added to acid and hydrogen gas is produced.
d.
iron combines with oxygen to form rust.

Butadiene undergoes a reaction at a certain temperature in the gas phase as follows: 2c4h6(g) --> c8h12(g) the following data were collected for this reaction: time (min) [c4h6] (m) 0 0.36 15 0.30 30 0.25 48 0.19 75 0. determine the order of the reaction and the rate constant. 1st order and k = 4.3x10 -4 s-1 1st order and k = 2.3x10-4 s-1 2nd order and k = 4.3x10-4 s-1 2nd order and k = 2.3x10-4 s-1 zero and k = 4.3x10-4 s-1

What is the mass of sodium in 3 moles of sodium chloride

Which statement is best described as a atom