Which of the following indicates an exothermic reaction?
O
O
A. A+B_heat , C+D
B. A + B + heat → C+D
C. A+B
→ C + D + heat
D. A + B + heat → C + D + heat

quartz

explanation:

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.