The number following the name of the element is the number of subatomic particles inside the nucleus of the atom. This means that it is the mass number of the isotope. The average atomic mass of the element is the sum of the products of the percentage abundance and mass number of the naturally occurring isotopes.
Since, the average atomic mass of the hydrogen is nearest to 1 then, the most abundant isotope should be hydrogen-1.
A. They speed up chemical reactions
Answer:
A is a physical change, no atoms are being lost its still in it original form
B is a chemical change, it is losing atoms and changing into a new substance
Explanation:
