Can someone help me please?

How many neutrons does a atom of cobalt have?

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space

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