Answer: Electrons
Explanation:
An atom a fundamental piece of matter and it is composed of small particles called protons, neutrons (both of them found in the nucleus) and electrons. The charge of the proton and electron are the same size but opposite.
A chemical bond is an attraction between atoms that enables the formation of different chemical compounds. Covalent bonds are formed when atoms share electrons, which are found in shells or orbitals that surround the nucleus of an atom. The number of electrons found in the outer most shell of an atom determine its reactivity, and those are the atoms that can be shared. Those electrons found on this outermost energy level are known as valence electrons and they are shared between atoms to form a covalent bond.
