2-
a gas
non-metal
it only has an appearance when it is in liquid form and then it is a light pink colour
The formula without the coefficient has 2 oxygens, but multiply that by the coefficient of 6 gets you 12 oxygens. In chemistry, a coefficient in front of a compound applies to everything in that compound even though there aren't any parentheses.
molecular weight of NiSO4.7H2O is 1101.3 and it has 11 oxygens. So percentage of oxygen = (7 x 16) / 1101.3 = 112 / 1101.3 = 0.102 or 10.2%
2-
it has no oder .
Oxygen is in p block. it is a useful gas. oxygens atomic number is 8.
a gas
Colourless gas
5
O2
Liquid density at boiling point (90 K) is 1.141 g·cm−3
One.
hydrogen and 2 oxygens
It is 15.999