Question

Describe the composition of an atom.

Answer 1

The atom consists of a tiny nucleus surrounded by moving electrons.  The nucleus contains protons, which have a positive charge equal in magnitude to the electron's negative charge.  The nucleus may also contain neutrons, which have virtually the same mass but no charge.

Answer 2

An atom consists of a positively charged nucleus surrounded by nagatively charged electrons moving in different orbitals. Baring hydrogen nucleaus, where neutron is absent, all other nucleus contains both protons and neutrons. Protons have positive charge and their number defines the element. Neutrons are neutral particles, having almost same mass as proton. The mass of nucleaus alsmost decides the mass of the elements, as electron is about 2000 times lighter than proton. In an atom, more than 99.99 % volume is free space.