ATOMS AND MOLECULES

Atoms:

Ø It is the smallest constituent unit of matter that possess the properties of the chemical element.

Ø Atoms don’t exist independently, instead, they form ions and molecules which further combine in large numbers to form matter that we see, feel and touch.

Molecules:

Ø A molecule is defined as the smallest unit of a compound that contains the chemical properties of the compound.

Ø Molecules are made up of groups of atoms.

Relative atomic mass of elements (C-12 Scale):

Atomic mass of some elements:

Isotopes of oxygen:

Classification of molecules:

AVOGADRO HYPOTHESIS:

Ø The Avogadro’s law states that “equal volumes of all gases under similar conditions of temperature and pressure contain equal number of molecules”.