The atomic mass of an element can be approximated by adding the number of plus the average number of
a. protons; electrons
b. protons; neutrons
c. neutrons; electrons

Option (B) is the correct answer.

Explanation:

Atomic mass is defined as the summation of total number of protons and neutrons present in an element.

On the other hand, atomic number means the total number of protons present in an element.

For example, atomic number of sodium is 11 and number of neutrons present in it are 12.

Hence, atomic mass of sodium = no. of protons + no. of neutrons

                                                    = (11 + 12) amu

                                                    = 23 amu

Therefore, we can conclude that the atomic mass of an element can be approximated by adding the number of protons plus the average number of neutrons.

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.