Question

the element titanium has five naturally occurring isotopes.
what information about these isotopes is needed to determine titaniums average atomic mass?
choose 2 answers:
a the atomic mass of each isotope
b the atomic number of each isotope
c the relative abundance of each isotope
d the number of neutrons in each isotope

Explanation:

To determine the average atomic mass of an element with multiple isotopes, the formula is:

$$\text{Average atomic mass}=\sum_{i = 1}^{n}(m_i\times a_i)$$

where \(m_i\) is the atomic mass of the \(i^{th}\) isotope and \(a_i\) is the relative abundance (expressed as a decimal) of the \(i^{th}\) isotope.

The atomic number of an isotope is the same for all isotopes of a given element (since isotopes have the same number of protons). The number of neutrons can be calculated from the atomic mass and atomic number (\(N = A - Z\), where \(A\) is the atomic mass and \(Z\) is the atomic number), but it is not directly used in the formula for average atomic mass.

Answer:

A. the atomic mass of each isotope, C. the relative abundance of each isotope