How many electrons does oxygen have in its 2nd energy level?

If a particle has z = 25 and 23 electrons, what is its charge?

Which method would be best to separate a mixture of sand and gravel

At 35.0°c and 3.00 atm pressure, a gas has a volume of 1.40 l. what pressure does the gas have at 0.00°c and a volume of 0.950 l? which equation should you use? p2= p1v1t2/t1v2what is the pressure of the gas? 3.92 atm these are the answers