Please help I’ll mark you brainiest if it’s correct. There is 3 answers to this one!

Which type of orbits are found in the principal energy level n = 2 a - s b - s, f c - s, d d - s, p e - s, p, d

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

Wind and moving water provide energy. chemical mechanical thermal none of the above