In each of the following cases, give the number or the element symbol represented by X. 40 18 X
X 20 Ca
31 X P

0.09 moles of sodium sulfate in 12 ml of solution

What method(s) do plants use to obtain nitrogen? select all that apply. absorb it from the atmosphere use bacteria to convert nitrogen to usable form obtain usable nitrogen compounds from the soil absorb nitrogen from water taken in at the roots

What shape would a molecule with two bound groups and two lone pairs have?