Period are going left to right across the periodic table
Groups are going up to down on the periodic table
How does the law of conservation of mass apply to this reaction: C2H4 + O2 → H2O + CO2?
The volume of one mole of any gas at Standard Temperature and Pressure (1 atm and 0 degrees Celsius [273K]) is 22.4 L.
Hmm... I'm unsure but its either B or D.