How many moles are in 159 Liters of He2F?
O 9 moles
0 7 moles
5 moles
O 8 moles

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

im not exactly sure but i think its b!

the electron configuration that you gave me has 16 electrons ergo it has 16 protons ergo it is the element sulfur.