The atomic number,atomic mass,valence electrons and the formula for calculating the number of neutrons is also given.The following table has been completed below in the attachment.
Explanation:
Atomic Number:the number of protons /electrons present in the nucleus of an atom is called the atomic number.
Mass Number/Atomic Mass:the number of protons and neutrons present in a nucleus
<u>Example:</u>
;here;6 implies the atomic number and 12 implies the mass number/atomic mass
<u><em>No.of neutrons=Mass number-Number of protons</em></u>
Valence electrons:the number of electrons present in the outer most shell of an atom are called valence electrons
<u>Example:</u>If we consider a carbon atom;as its <em>e</em><em>lectronic configuration is2,4 and</em> it belongs to 4th group.Therefore the number of valency electrons in carbon is <u>4.</u>