Here's why:
* Protons and Neutrons: The nucleus of an atom contains protons and neutrons. These particles are much heavier than electrons.
* Electrons: Electrons orbit the nucleus and have a very small mass compared to protons and neutrons.
* Atomic Mass Unit (amu): The mass of an atom is typically expressed in atomic mass units (amu). One amu is approximately equal to the mass of a proton or neutron.
In summary: While electrons contribute to the overall structure of an atom, the vast majority of the atom's mass is found in the nucleus due to the presence of protons and neutrons.
