If you started with 1000 units of a radioactive element that has a half-life of 2,500 years, how many half-lives will the material have gone through in 7500 years? (Show work and explain answer).

At an atmospheric pressure of 870 mm hg of 21% oxygen, the partial pressure of oxygen is

Which of the following is not an indication of a chemical change? A. fracture formation. B. energy transfer. C. precipitate formation. D. gas production

Which of the following is the correct formula for the compound disulfur pentoxide

Why do the atoms in a molecule want to be so far apart? (Mention Electron domains/Electrons)

What usually happens when a newborn smells vinegar, rotten eggs or ammonia?

A specific, electrically neutral atom of boron has 5 protons, 5 electrons, and 6 neutrons. what is the mass number of this atom of boron? 6 5 11 16

When does hail happen?

For the reaction, calculate how many moles of the product form when 0.012 mol of O2 completely reacts. Assume that there is more than enough of the other reactant. 4Al (s) + 3O2 (g) →2Al2O3 (s) Express your answer using two significant figures.

Nuclei with too many or too few neutrons are?

Be sure to answer all parts. Enter the formula for potassium dihydrogen phosphate and determine its molecular (formula) mass.