TRUE OR FALSE ( will give brainliest ) - elements are composed of two or more kinds of material.
- compounds are composed of one kind of material
- different properties are shown after an element is broken down
- mixtures are made by a physical change
- compounds have a definite composition
- mixtures have variable composition

false, compounds are but elements are not

Explanation:

have a great day

false, false, false, true, true, true

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