Ch 4 history and structure of the atom
in which of the following sets is the symbol, the number of protons, and the number of electrons given correctly for the element, chlorine?

a) Cl, 17 protons and 17 electrons

Explanation:

The elements of group 17 are called halogens. These are six elements Fluorine, Chlorine, Bromine, Iodine, Astatine. The atomic number of chlorine is 17. Its means it has 17 protons and 17 electrons.

The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom. Thus the atomic mass of chlorine will be 17+18 = 35 amu

Number protons = 17

Number of electrons = 17

Number of neutrons = 18

Properties of Chlorine:

1. it is greenish-yellow irritating gas.

2. its melting point is 172.2 K

3. its boiling point is 238.6 K

4. it is disinfectant and can kill the bacteria.

5. it is also used in manufacturing of paper, paints and textile industries.