EVERYDAY SCIENCE

Detailed explanation-1: -Together, the number of protons and the number of neutrons determine an element’s mass number: mass number = protons + neutrons. If you want to calculate how many neutrons an atom has, you can simply subtract the number of protons, or atomic number, from the mass number.

Detailed explanation-2: -The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus. The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).

Detailed explanation-3: -The mass number of an atom is equal to the number of protons plus the number of neutrons that it contains. In other words, the number of neutrons in any atom is its mass number minus its atomic number. Although all atoms of a given element must have the same atomic number, they need not all have the same mass number.

Detailed explanation-4: -The positively charged protons tend to repel each other, and the neutrons help to hold the nucleus together. The number of protons is the atomic number, and the number of protons plus neutrons is the atomic mass. For hydrogen, the atomic mass is 1 because there is one proton and no neutrons.

Detailed explanation-5: -The given statement is false (F). The mass of the electron = 9.1 ✕ 10⁻³¹ kg. The mass of the proton = 1.673 ✕ 10⁻²⁷ kg. The mass of a neutron is equal to 1.675 ✕ 10⁻²⁷ kg.