GENERAL KNOWLEDGE

Detailed explanation-1: -The atomic number is the number of protons in the nucleus of an atom. The number of protons define the identity of an element (i.e., an element with 6 protons is a carbon atom, no matter how many neutrons may be present).

Detailed explanation-2: -The atomic number is the number of protons in an atom, and isotopes have the same atomic number but differ in the number of neutrons.

Detailed explanation-3: -Atoms are made of extremely tiny particles called protons, neutrons, and electrons. Protons and neutrons are in the center of the atom, making up the nucleus. Electrons surround the nucleus. Protons have a positive charge.

Detailed explanation-4: -The atomic number of an atom is equal to the number of protons in the nucleus of an atom or the number of electrons in an electrically neutral atom. For example, in a sodium atom, there are 11 electrons and 11 protons. Thus the atomic number of Na atom = number of electrons = number of protons = 11.

Detailed explanation-5: -Because electrons have virtually no mass, just about all the mass of an atom is in its protons and neutrons. Therefore, the total number of protons and neutrons in an atom determines its mass in atomic mass units (Table 4.5.