An atom has 11 protons, 12 neutrons, and 10 electrons. What is the charge?

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.

What metric units would you use to measure the thickness of a key

Large helium-filled balloons are used to lift scientific equipment to high altitudes. what is the pressure inside such a balloon if it starts out at sea level with a temperature of 10.0ºc and rises to an altitude where its volume is twenty times the original volume and its temperature is – 50.0ºc ?