Question

Is oxygen a gas yes no and why

Answer 1

any matter can be transformed into all (common) different types of matter (solid, liquid, gas) by heating it or cooling it. It depends on the strength of attraction between the individual molecules that make that substance up and the atmospheric pressure. These dictate it's melting point and boiling point. At 1 atm, oxygen is solid below -218.79 °C , liquid between -218.79 ° and -182.962 °C, gas above-182.962 °C.*

So at room temperature it's a gas.

* http://en.wikipedia.org/wiki/Oxygen

Answer 2

yes b/c it has free particles