Sodium-24 is a beta emitter used in diagnosing circulation problems. It has a half-life of 15 hours. What percent of sodium-24 remains are 45 hours

In an energy pyramid, which level has the most available energy?

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

Astudent carefully transfers 30 g of water and 30 g of alcohol in a glass tube, forming two layers and filling the tube completely. after sealing the tube, the student mixes the solutions, and notices a bubble that forms in the tube. what is the mass of the contents in the glass tube after mixing?