an element has a half-life of 5.0 days. How many days would pass before only 1/8th of the original amount of a sample of this element remained

You may expect bonds between two atoms which each have n covalent lonic metallic hydrogen

What is conserved in the reaction shown below? h2(g) + cl2 (g) --> 2hcl(g)a. mass onlyb. mass and moles onlyc. mass, moles, and molecules onlyd. mass, moles, molecules, and volume

What is the mass of phosphorous in a 51-kg person