X-122 has an abundance of 34.44%

amu = 42.02

Explanation:

to calculate the average mass, first convert the percentages to decimals by dividing by 100. then, multiply the decimal by the mass number for each isotope, then add them together.

( 0.3444 x 122 ) = 42.0168 round that answer to 42.02

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.