4. Classifying The following are balanced equations for chemical reactions. Classify each of the equations as synthesis, decomposition, or replacement. a. 2 Al + Fe2O3 - 2 Fe + Al2O3 b. 2 Ag + S - Ag2S C. CaCO3 > CaO + CO, d. 2 NO + 0,- 2 NO

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements

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.

pv=nrt

explanation: