Afictitious element z has an average atomic mass of 223.06 u.223.06 u. element z has two naturally occuring isotopes. the more abundant isotope has an exact mass of 223.95 u223.95 u and a relative abundance of 65.51%.65.51%. calculate the exact mass of the second isotope.

221.37 u

Explanation:

The formula for the calculation of the average atomic mass is:

Given that:

For first isotope:

% = 65.51 %

Mass = 223.95 u

For second isotope:

Since the element has only 2 isotopes, so the percentage of second is 100 - first percentage.

% = 100 %  - 65.51 %  = 34.49 %

Let, Mass = x u

Given, Average Mass = 223.06 u

Thus,  

Solving for x, we get that:

x = 221.37 u

Thus mass of second isotope = 221.37 u

the only liquid elements at standard temperature and pressure are bromine (br) and mercury (hg). although, elements caesium (cs), rubidium (rb), francium (fr) and gallium (ga) become liquid at or just above room temperature.

explanation: