A standard oxygen tank is rated for 3000 PSI of pressure. Any more than that, and it risks exploding. If an oxygen tank has 2500 PSI of pressure in it at room temperature (294 K), how hot could it get before reaching 3000 PSI of pressure?

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

How to convert a density of 0.791g/cm3 to lb/ft3