An atom of lithium-7 has an equal number of
(1) electrons and neutrons
(2) electrons and protons
(3) positrons and neutrons
(4) positrons and protons

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

No copying 15 pts how does a free-body diagram tell you about the net force on an object?

How do you know when a chemical reaction has occurred