Which is an example of a compound ? sand , gold , water , iodine

 Water

Explanation:  Compound is a substance which is formed by the linkage of different or same kind of atoms.

It is absically composed of two or more elements.

Thus out of the given options, sand is composed of Silica (Si) , gold (Au) is the single element, Iodine (I2) is an diatomic element itself.

Water is made up of  2 moles of hydroge and one mole of oxygen. Thus it will be considered as a compound.

wher is the rest of the question

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.