Why do atoms have electrons?
Electrons are one of the fundamental particles in atoms. They neutralise the charge of an atom, their negative charge balancing out the positively charged protons; that is why there’s always an equal number of electrons and protons in an atom. Electrons are also responsible for atom bonding. Atoms always want a full outer shell of electrons and, to this end, they gain, lose or share electrons with other atoms, often forming new materials in the process. As electrons are the part involved in bonding, the configuration of electrons in an atom is what gives an element its specific chemical and physical properties.
Answered by Scout Davies, Science Museum explainer.