A student is writing a formula for a compound. What must the student always remember to include? a. At least one number written large as a coefficient

b. At least two lowercase letters

c. Each element must be represented with a capital letter

d. At least one number written low as a subscript

PLEASE HELP!!

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.

there are two significant figures.