Helium is an odorless, colorless gas at room temperature. It is less dense than air. That's why helium balloons float. It is a non-reactive gas, a member of the Noble gas family. Its melting point is -272.2 oC and its boiling point is -268.93 oC. Physical properties of Helium are? (*more than 1 answer) A. It’s lack of color (colorless)
B. It’s non-reactivity
C. the fact that it’s less dense than air
D. it’s boiling point of -268.93 oC

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.

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