I would say Na. Oxygen has 2 valence electrons and when reacting with other molecules, the ones with the fullest or emptiest shells will react the least. Both H2 and Na are in the Alkali Metals in the first row, but since H2 has 2 molecules, it would use more oxygen than Ana
How difficult it is to change an objects motion. Think of a tablecloth; it takes energy to move it from underneath objects on the table, and it takes energy to move the objects themselves on the table.
First, you convert liters to moles.
Usually you have to go to grams but this is STP.
Get moles directly by dividing the 4 by STP (22.4)

About

or 0.18 moles whichever your teacher prefers
<span>explain why the dissolved component does not settle out of a solution -
</span><span>Before saturation, there are attractive forces between solute and solvent. after saturation, the capacity for the attractive forces is reached and no more solute can be dissolved</span>