Misc: radioactive carbon, used for dating fossils?

Questions

The famous cow used as the corporate symbol on all Elmer's products is actually named ----------, and she is the spouse of Elmer, the steer who the company is named after.?

There is no mention of cats or rats in the ----------?

The optimum depth of water in a birdbath, says the Audubon Society of America, is two and a half inches. Less water makes it difficult for birds to take a bath; more makes them ----------?

The fastest animal on four legs is the ----------?

Some more names for groups of animals... a bale of turtles, a clowder of cats, a charm of goldfinches, a gam of whales, a knot of toads, a ---------- of tigers.?