The period tells us the number of an element has. A. Valance electrons
B. energy levels

At stp, what is the volume of 1 mole of co2?

Adilute aqueous potassium nitrate solution is

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 ?