Question

Element X has two isotopes. The table gives information about these isotopes.

Isotope Atomic Mass (amu) Abundance (%)
X-63 62.9296 69.15
X-65 64.9278 30.85
The average atomic mass of element X is
amu.

Answer 1

63.55

Step-by-step explanation:

This is just the rounded version of the answer above. The first person is correct.

The blank wants the answer rounded the the nearest hundredth

Answer 2

Average Atomic Mass = 63.5460 amu

Step-by-step explanation:

Data Given:

Atomic Mass of ⁶³X = 62.9296 amu

Natural Abundance of ⁶³X = 69.15 %

Atomic Mass of ⁶⁵X = 64.9278 amu

Natural Abundance of ⁶⁵X = 30.85 %

Formula Used:

Average Atomic Mass = [(Atomic Mass of ⁶³X × Natural Abundance of ⁶³X) + (Atomic Mass of ⁶⁵X × Natural Abundance of ⁶⁵X)] ÷ 100

Putting values,

Average Atomic Mass = [(62.9296 × 69.15) + (64.9278 × 30.85)] ÷ 100

Average Atomic Mass = [(4351.5818) + (2003.0226)] ÷ 100

Average Atomic Mass = 6354.6044 ÷ 100

Average Atomic Mass = 63.5460 amu