Mass number,atomic number and change i guess
The answer to this question is a
To satisfy the law of conservation of mass
The scientist thought that the
atom was the smallest particle in the universe is John Dalton. He established
the atomic theory which consists of five; elements are made of extremely small
particles called atoms, atoms of different element have different sizes, mass
and physic – chemical properties, atoms cannot be divided further, destroyed or
created, atoms can combine to form compounds and in chemical reaction, atoms
can be combined, separated or rearranged. Hope this helps!!