Can someone help me with this question?

Acylinder is filled with 2.00 moles of nitrogen, 3.00 moles of argon and 5.00 moles of helium. if the gas mixture is at stp, what is the partial pressure of the argon

Name the element in group 17, period 2. (periodic table)

As air becomes more dense, (select all that apply) o. air weighs less o. gas molecules are closer together o. air is colder o. air weighs more o. gas molecules are further apart o. air is hotter