Identify, by letter: a gas that reacts with water to produce acid rain.
Identify, by letter: two gases which exist as diatomic molecules.
Identify, by letter: a gas that bleaches damp litmus paper.
Identify, by letter: a gas which is used as an inert atmosphere in lamps.
Identify, by letter: two gases which are found in clean dry air.
Identify, by letter: two gases which are found in refinery gas.
What does covalent bond mean?
Complete the dot-and-cross diagram so that it shows the electron arrangement in one NF$_3$ molecule. Show only the outer-shell electrons. The diagram contains a central N atom with three F atoms around it.
What does the term mixture mean?
State the percentage of oxygen in clean dry air, rounded to the nearest whole number.
Describe the stages in the industrial process that is used to separate nitrogen and oxygen from clean dry air. Use scientific terms in your answer.
Which physical property makes it possible to separate nitrogen and oxygen?