Chemical Changes

Alkalis turn red litmus paper ______ and have no effect on blue litmus paper.

A salt is an ionic compound which is made up of two ions. What are they?

• Cation and ion

• Anion and bation

• Anion and cation

• bation and cation

A cation is a positive ion. For it to be positive it needs more ________.

• electrons

• neutrons

• protons

• atoms

Alkalis have a _____ taste.

Both acids and alkalis could be corrosive.

• True

• False

• only acids

• only alkalis

Bases are substances that react with acids to form_______

• salt

• salt and water

• hydroxide ions

• salt + ammonia

What is considered neutral?

• tomato

• water

• salt

• blood

pH above 7

• the more strongly acidic the solution

• equal

• the more strongly alkaline the solution

Allows us to measure exact pH of a substance.

• Universal indicator

• pH paper

• pH meter or pH sensor

• all of the above

What colour is a neutral substance on the pH scale?

• purple

• orange

• green

• hello