Question

why an atom is electrically neutral though it contains charged particles ?

Answer 1

An atom consists of three particles - the protons, neutrons and electrons. The protons and the neutrons are present in the nucleus which is the center of the atom and the electrons revolve around the nucleus in different energy levels. While the protons are positively charged, the electrons are negatively charged. Thus electrons and protons carry equal but opposite charges. Also, the neutrons do not possess any charge. As the number of protons are equal to the number of electrons, the total negative charge due to electrons and positive charge due to protons balance each other. This makes the atom electrically neutral.