The mass of an atom is mostly in the nucleus. Though electrons that orbit the nucleus also have mass, their masses are so small (each electron is 1/1823th the mass of a proton), the mass of any atom would be 99.9% in the nucleus.
In the nucleas. Ray
The Mass Number.
mass energy and binding energy
A nucleas is something in an atom.
true
Yes
In the nucleas
protrons, neutrons, electrons
they are the outermost electrons orbiting the nucleas
The nucleus of an atom is located at the center of the atom. It contains protons and neutrons, which are held together by strong nuclear forces. The nucleus makes up the majority of the atom's mass and has a positive charge due to the protons it contains.
It has 20 neutrons and 20 protons.
This question does not seem to make sense in its present wording. If you are asking what are the three basic particles that make up an atom, they are the electron, the proton and the neutron. The protons and neutrons form the nucleas (center) of the atom and are considered to comprise most or all of its weight (mass). The electrons circle around the nucleas in orbits called "shells" and are considered to be responsible for the reactivity of the atom with itself or with other atoms. They contribute nothing, or nearly nothing, to the atomic mass.