All three molecules of the illustration entitled "pentane isomers: "

have the same chemical formula
contain the same number of carbon atoms
are isomers

1. have the same chemical formula

2. contain the same number of carbon atoms

3. are isomers

Explanation:

All 3 statements are correct.

12 is it do you think so

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