1. cl2 and br2 have approximately the same shape and neither is polar.
(a) upon cooling, both cl2 and br2 form solids. why?
(b) at 25°c, chlorine (cl2) is a gas whereas bromine (br2) is a liquid. why?

fe 55.85 g/mol and h2o 18.02 g/mol.

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally