In the following reactions first identify the substance that is oxidized and the one that is reduced. then identify the oxidizing and reducing agents.
a. 2li(s)+ f2(g) --> 2lif(s)
b. fe(s) + cuso4(aq) --> feso4(aq)+ cu(s)

So the Li is oxidized and the F is reduced.
when you become negative you gain electrons=reduction

The atom that causes the reduction is the reducing agent, so since the Li caused the F to be reduced it is the reducing agent.And vice versa. The F is the oxidizing agent.

B) Fe is oxidized, but the element that is reduced is Cu.The charge must change for it to be oxidized or reduced.The SO4 is -2 the whole time.Fe is the reducing agent and Cu is the oxidizing agent.

Whatever is oxidized is the reducing agent, and whatever is reduced is the oxidizing agent.

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.

he uptake of drugs from the intestine is often strongly influenced by diffusion. for example, consider a water-insoluble steroid for treating inflammation that is solubilized in aggregates of detergent molecules, called micelles. these micelles, aggregates of 80 soap molecules, have a molecular weight of 24,000, a diameter of 2.6 nm, and a charge of -27. the positively charge ions (counterions) in this system are na".