Q 01/05

What is nitrogen's atomic number?

A) 7

B) 8

C) 9

D) 14

Answer · why

A) 7

Its symbol is N and it heads group 15 of the periodic table.

Q 02/05

Roughly what percentage of Earth's atmosphere is nitrogen?

A) 78%

B) 81%

C) 85%

D) 90%

Answer · why

A) 78%

Oxygen is about 21% and argon just under 1%.

Q 03/05

What is the name for the group of elements headed by nitrogen?

A) Chalcogens

B) Halogens

C) Pnictogens

D) Noble gases

Answer · why

C) Pnictogens

The name comes from the Greek for 'to choke', a nod to nitrogen's asphyxiating nature.

Q 04/05

Which Scottish physician is credited with discovering nitrogen in 1772?

A) Joseph Black

B) Daniel Rutherford

C) William Cullen

D) James Watt

Answer · why

B) Daniel Rutherford

He called it 'noxious air' and distinguished it from Black's 'fixed air', carbon dioxide.

Q 05/05

What later career did nitrogen's discoverer pursue at the University of Edinburgh?

A) Dean of divinity

B) Professor of law

C) Professor of anatomy

D) Professor of botany

Answer · why

D) Professor of botany

He was also Regius Keeper of the Royal Botanic Garden Edinburgh from 1786 to 1819.