Two common gem varieties of the mineral corundum are and a: halite; fluorite b: ruby; sapphire c: amethyst; citrine d: hematite; magnetite

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

Determine the maximum r-value of the polar equation r =3+3 cos 0

The experiment was repeated many years later but the gases were mixed in a different type of container. a white solid was obtained which was xenon fluoride. predict whether you think 1) krypton and 2) radon will react with fluorine. explain reasons for your predictions