What do you mean by mass combining?
Solution:-
The question is not clear, So I am posting the most probable answer here.
When two or more than two element combine in a ratio then the sum of the mass of the element can be said to be combined mass.
The question is not clear, So I am posting the most probable answer here.
When two or more than two element combine in a ratio then the sum of the mass of the element can be said to be combined mass.