Q 01/05

What is the chemical formula of common salt?

A) CaCl2

B) NaCl

C) KCl

D) NaOH

Answer · why

B) NaCl

Sodium chloride is the source of two essential dietary minerals, sodium and chlorine.

Q 02/05

What is the mineral name for natural crystalline salt?

A) Gypsum

B) Calcite

C) Sylvite

D) Halite

Answer · why

D) Halite

Its crystals are translucent cubes; impurities can tint them blue or purple.

Q 03/05

Around when does some of the earliest evidence of salt processing, in present-day Romania, date from?

A) 1000 BC

B) 3000 BC

C) 6000 BC

D) AD 500

Answer · why

C) 6000 BC

Neolithic people at Poiana Slatinei boiled spring water; a saltworks at Xiechi Lake in China is about as old.

Q 04/05

Which Bulgarian salt-mining settlement is thought to be Europe's first city?

A) Plovdiv

B) Varna

C) Provadia

D) Solnitsata

Answer · why

D) Solnitsata

It supplied the Balkans with salt from about 5400 BC.

Q 05/05

Roughly how much salt is produced worldwide each year?

A) 30 million tonnes

B) 3 million tonnes

C) 300 million tonnes

D) 3 billion tonnes

Answer · why

C) 300 million tonnes

Only a small share is eaten; most goes to make chemicals such as caustic soda and chlorine.