Atomic Structure

All matter is composed of atoms which contain protons, neutrons and electrons. The electrons are in the empty space around the nucleus and the protons and neutrons are in the nucleus of the atom. The electrons are held in the atom because they are attracted to the positively charged nucleus. The atom is held together by the positive and negative attractions. The cathode ray is used mainly in television today, a cathode ray is a ray of negatively charged electrons. When you place the positive side of the magnet to the cathode ray, the ray moves close to it because the negative charges are attracted to the positive ones in the magnet. To identify an isotope, the number that is added is called the mass number. The mass number is the sum of the protons and neutrons in the nucleus of an atom. The mass number for potassium is 40. The atomic number is the number of protons in the nucleus of an atom. If you subtract the mass number from the atomic number, you will then know how many neutrons are in the particular atom.
For the the chemical symbol V; the element name is vanadium, there is only one proton and only one election is this element. For the chemical symbol Mn; the element name is manganese, this element has 25 protons and 25 electrons. For the chemical symbol Ir; the element name is iridium, the element has 77 protons and electrons. For the chemical symbol S; the element name is sulfur, this element has 16 protons and electrons.
132/55 means the element has 77 neutrons, 55 electrons and protons. 70/30 means the element has 40 neutrons and 30 protons and electrons. 163/69 means the element has 94 neutrons and 69 protons and electrons. 59/27 means the element has 32 neutrons and 27 protons and electrons.