Which subatomic particle has the least mass

Electron

Explanation:

According to the Bohr model, an atom contains three sub-atomic particles. These particles are electrons, protons and neutrons. Electrons are negatively charged, protons are positively charged and neutrons are neutral particles. Protons and neutrons are present in the nucleus. They are called nucleons. Electrons are present outside the nucleus.

Most of an atom's mass is in the nucleus because the atomic mass of the proton is 1.0073 AU, the atomic mass of the neutron is 1.0078 AU. The atomic mass of the electron is 0.00054858 AU.

Thus, the sub-atomic particle the electron has least atomic mass.  

ionic bonds are two oppositely charged ions that attract. a sodium ion has a 1 positive charge; a chloride ion has a 1 negative charge. sodium and chloride have oppostive charged ions that attract which forms an ionic bond. a chemical bond formed when two atoms share electrons is called