Find the number of moles that are in 2.23 g of Li 2 O and report it with the correct significant figures.

Cobalt-60 is an artificial radioisotope that is produced in a nuclear reactor and is used as a gamma-ray source in the treatment of certain types of cancer. if the wavelength of the gamma radiation from a cobalt-60 source is 1.00 × 10-3 nm, calculate the energy of a photon of this radiation.

The electromagnetic force acts between what

1. list three scientific reasons cockroaches may fly.