Question

Why did the scientist choose oxygen as the standard unit earlier?​

Answer 1

Answer:

Initially 1/16th of the mass of naturally occurring oxygen was taken as the atomic mass unit because this unit gave masses of most of the elements as whole numbers.

Answer 2

Answer:

Initially 1/16th of the mass of naturally occurring oxygen was taken as the atomic mass unit because this unit gave masses of most of the elements as whole numbers.

Explanation:

• At first mass of hydrogen was chosen to measure the relative masses of other elements because it is the lightest element and can compare with all.  
• But later oxygen is chosen to calculate the relative mass of elements because oxygen is considered as more reactive than the hydrogen and it gives relative masses of other elements in the whole number which make it easier to calculate.
• It reacted with large number of elements and formed compounds.
• The atomic mass unit gave masses of most of the elements as whole numbers.