Question

1. base your answer to the following questions on the data table below, showing isotopes of neon

isotope	atomic mass (atomic mass units, amu)	percent natural abundance
$^{21}$ne	20.99	0.3%
$^{22}$ne	21.99	8.8%

a) in terms of atomic particles, state one difference between the three isotopes of neon.
b) show a correct numerical setup for calculating the average atomic mass of neon.

Explanation:

Step1: Recall isotope definition

Isotopes of an element have the same number of protons but different numbers of neutrons.

Step2: Set - up for average atomic mass

The formula for average atomic mass is $\sum_{i = 1}^{n}(m_i\times p_i)$, where $m_i$ is the atomic mass of isotope $i$ and $p_i$ is the percent - abundance of isotope $i$ (expressed as a decimal).
For neon:
The set - up is $(19.99\times0.909)+(20.99\times0.003)+(21.99\times0.088)$

Answer:

a) The number of neutrons is different in the three isotopes of neon.
b) $(19.99\times0.909)+(20.99\times0.003)+(21.99\times0.088)$