1. Say whether the following statements are true or false and explain why:

a) According to Dalton’s theory, matter is formed of indivisible particles called atoms.

b) There are three types of subatomic particles: the proton, the neutron and the shell.

c) The periodic table has 8 rows, or periods, and 19 columns, or groups.

d) All the elements in the same group or family have not similar chemical properties.

e) We distinguish three large groups of elements on the periodic table,

depending on their properties. These groups arte the metals the semimetals, the noble gases.

f) The atomic number, Z, is the number of neutrons in the atom.

g) If an atom gains electrons, it becomes a cation.

h) A molecule is a group of a certain number of atoms bonded together.