Q 01/05

Which metal forms the skin of the Statue of Liberty, which turned from shiny brown to green by reacting with air?

A) Bronze

B) Copper

C) Zinc

D) Nickel

Answer · why

B) Copper

Copper on the statue was reddish-brown and shiny when it was built, but within twenty years it had turned green. That green layer now protects the met...

Q 02/05

Which candy makes Diet Coke erupt in a geyser, not by a chemical reaction but by helping dissolved gas escape?

A) Mentos

B) Skittles

C) Tic Tacs

D) Altoids

Answer · why

A) Mentos

Mentos are covered in millions of microscopic pits, and each one gives the dissolved carbon dioxide a place to form bubbles. Nothing new is made, so t...

Q 03/05

What forms inside a disposable hand warmer as the powder in it reacts with air and heats up?

A) Soot

B) Chalk

C) Rust

D) Clay

Answer · why

C) Rust

Rust gives off heat as it forms, and that is the whole trick. Tearing open the wrapper lets air reach the iron, and the pouch then stays warm for many...

Q 04/05

Which liquid from the medicine cabinet breaks down into water and oxygen to make the foam called elephant's toothpaste?

A) Rubbing alcohol

B) Nail polish remover

C) Calamine lotion

D) Hydrogen peroxide

Answer · why

D) Hydrogen peroxide

Hydrogen peroxide normally breaks down far too slowly to notice. The demonstration adds a helper chemical to speed it up, and dish detergent to trap t...

Q 05/05

Which kitchen powder fizzes with vinegar in a model volcano because the reaction gives off carbon dioxide gas?

A) Baking soda

B) Corn starch

C) Icing sugar

D) Plain flour

Answer · why

A) Baking soda

Baking soda does the same job in cakes and cookies. An acid in the mix, such as cream of tartar, sets off the gas that puffs up the dough.