A group of 4 stars form at the same time in a cluster. Star A is the mass of our Sun, Star B is 4 solar masses, Star C is 0.4 solar masses and Star D is 12 solar masses. How many stars are left on the main sequence after 8 billion years? 0, 1, 2, 3, or 4?

po-215 i got it right on the quiz

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.