If we want to know how many neutrons an element has we: a. look at Period Number ( row)
b. subtract Atomic Number from Atomic Mass
c. look at Atomic Mass (below element symbol)
d. look at Atomic Number (above element symbol)

Inside a flashbulb, oxygen surrounds a thin coil of magnesium. when the flashbulb is set off, a chemical reaction takes place in which magnesium combines with oxygen to form magnesium oxide. which of the chemical equations matches the reaction above? a. mg + o2 mgo2 + energy b. 2mg + o mg2o + energy c. 2mg + o2 2mgo + energy d. mg + o mgo + energy