4. Find the standard enthalpy of formation of ethylene, C2H4(g), given the following data: heat of combustion of C2H4(g) = â€"1411 kJ/mol; ď„H°f[CO2(g)] = â€"393. 5 kJ/mol; ď„H°f[H2O(l)] = â€"285. 8 kJ/mol.

h let me think

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.

sorry i was late, but i don't know what assignment your talking about, i'm in flvs as well, im in earth space science. but u are behind pace bc every class should be in the 3's or 4'