An atom of potassium-37 and an atom of potassium-42 differ in their total number of
(1) electrons (3) protons
(2) neutrons (4) positrons

thats a little if u want the answer just look it up on google thats what i do haha : )

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.