Q 01/05

What is helium's atomic number?

A) 1

B) 10

C) 2

D) 4

Answer · why

C) 2

Its symbol is He, and it heads the noble gas column of the periodic table.

Q 02/05

Helium takes its name from the Greek word for what?

A) The Sun

B) Light

C) Laughter

D) Air

Answer · why

A) The Sun

It was named after an unknown yellow line spotted in the solar spectrum in 1868, decades before anyone found it on Earth.

Q 03/05

To which group of the periodic table does helium belong?

A) The halogens

B) The noble gases

C) The alkaline earth metals

D) The alkali metals

Answer · why

B) The noble gases

It is the first member of the group and, after neon, the second least reactive element of all.

Q 04/05

Roughly what share of the ordinary matter in the universe is helium, by mass?

A) About 75%

B) About 2%

C) About 24%

D) About 50%

Answer · why

C) About 24%

Only hydrogen is more abundant; helium outweighs all the heavier elements put together more than 12 times over.

Q 05/05

During what event was helium first detected in sunlight, in 1868?

A) A great comet's passage

B) A transit of Venus

C) A large sunspot outbreak

D) A total solar eclipse

Answer · why

D) A total solar eclipse

Jules Janssen recorded the bright yellow line at Guntur, India, and it was at first assumed to be sodium.