electron
Adding a neutron to an atom's nucleus increases the atom's mass by the mass of the neutron itself. Neutrons are more massive than protons, so adding a neutron will increase the atom's total mass without changing its charge.
To find the molar mass of an atom, you need to add up the atomic masses of all the atoms in its chemical formula. This can be determined from the periodic table. The unit for molar mass is grams per mole.
The protons and the neutrons, because those are the only particles in the atom that contain quarks.
Neutrons and they are found inside the nucleus.
To add atoms in ChemDraw, select the "Atom" tool from the toolbar, then click on the drawing area where you want to place the atom. You can also use keyboard shortcuts to add specific atoms.
To calculate the weight of a mole of an atom in grams (molar mass), you add up the atomic masses of all the atoms in one mole of the substance. This can be found on the periodic table and is usually given in atomic mass units (amu). The molar mass is expressed in grams per mole.
Mass number/Atomic Mass
The electron.
we can not add neutron
Neutrons add mass and stability to an atom by increasing the atomic weight without changing the chemical properties. They also help to hold the nucleus together by balancing the repulsive forces between protons.
In the nucleus of the atom, protons and neutrons therein each add 1 atomic mass unit.
To the find the mass number of an atom you add the protons and neutrons. Meaning that the mass number of this atom is 12.