Phosphorus always has 15 protons; that is the definition of the element.
All phosphorus atoms have 15 protons (hence their atomic number of fifteen). Assuming the atom is neutral, it will also have an equal amount of electrons.
A neutral atom of phosphorus has 15 protons, 15 neutrons, and 15 electrons. Each proton has a positive charge, each neutron has no charge, and each electron has a negative charge, resulting in the atom being electrically neutral.
5
An atom of chlorine has 17 protons.
protons
The atom must have 8 electrons to make it have a neutral charge
If a neutral atom of sodium has 11 protons, it will have 11 electrons also.
A neutral atom with 12 protons will have 12 electrons in order to balance the positive charge from the protons.
8 protons
The number of electrons should = the number of protons.
There are 6 protons in a neutral atom of Carbon 13
An atom with 35 protons is iodine, which is a neutral atom. In a neutral atom, the number of electrons equals the number of protons, so it also has 35 electrons. Therefore, an atom with 35 protons has 35 electrons.