Why is an atom electrically neutral?. An atom is electrically neutral because the overall charge of an atom is zero. The atoms are made of three subatomic particles called protons, electrons and neutrons. Protons are positively charged particles, electrons are negatively charged and neutrons are neutral. The overall charge of an atom is zero because the atoms have an equal number of protons and electrons. The charge of both protons and electrons are of equal strength, therefore atoms having an equal number of protons and electrons are electrically neutral.
If the atom has lost or gained electrons then it will not be electrically neutral anymore. These atoms will be called ions. Ions will be positively charged or negatively charged. If an atom loses an electron it will have more number of protons. Therefore, the net charge of the atom will be positive and will be called cations. If an atom gains electrons, the number of electrons in the atom will be more than the number of protons. Hence, the net charge of the atom will be negative and is called anion.
Like charges will repel each other and unlike charges will attract each other. So, the positively charged atoms will attract electrons until it becomes neutral. Whereas, a negatively charged atom will repel some of the electrons till it becomes neutral.