Question

wht is atom?
The smallest tiny particles of matter which can't be divided further is called atom, i.e., an atom is the smallest building block of matter. For example: Sodium (Na), Hydrogen (H), Oxygen (O), etc.

Answer 1

A is correct answer

Explanation:

your answer is upside

Answer 2

Answer:

All substances are made up of atoms. An atom consist of positively charged proton negatively charged electron and neutral neutron. The central nucleus consist of protons and neutrons while electron revolve around the nucleus. Generally in an atom, the number of protons will be equal to number of electrons and this makes an atom.