Which of the following statement(s) `is//are` correct
A. Mass of one ca atom is `6.64xx10^(-23) g`
B. Volume of 18 g `H_(2)O` at 1 atm pressure and 273 K temperature is 22.4 L
C. Number of oxygen atoms in
D. `C_(4)H_(6)O_(2)` sample is 2, if this sample has 6 g atom hydrogen
