Question

Account for the following; a) Hydrogen is considered an element. b) Water is regarded as a compound

Answer 1

hydrogen is considered as an element

because it have contain electron and proton .
it have mass also

Water is regarded as a compound

it contains two elements hydrogen and oxygen that why water is considered as compound
water is also pure substance.

Answer 2

a ) Hydrogen is considered to be an element because, Hydrogen is made up of only similar type of Hydrogen atoms. Also Hydrogen cannot be broken down into further simpler compounds due to which they are known as elements. It's molecular formula is H₂

b ) Water is a compound as it has a molecular formula of H₂O. Since it contains both Hydrogen and Oxygen atoms it cannot be called as an element. Since it is a mixture of two elements in a particular molecular ratio, it is called as a compound.

Hope my answer helped !