How many grams of a 1000-gram radioactive sample are left after 3 half-lives? * 1 point 1000 grams 500 grams 250 grams 125 grams 2000 grams

Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.

How have the greenhouse gasses increased from the year 2000 to 2018