The following reaction occurs in a voltaic cell: Cu2++Zn→Zn2++Cu .

Which of the following reactions occurs at the cathode?

Cu2++2e−→Cu

Zn→Zn2++2e−

Cu2++2e−→Zn2++Cu

Cu2++Zn→Zn2++2e−

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

What is the energy in joules of a mole of photons associated with visible light of wavelength 486 nm?

Which of the following describes qualitative data? a) recording the temperature of a solid as it is warmed. b) noting the color of a solution as it is heated. c) measuring the volume of an object by water displacement. d) taking the mass of an object using a balance.