Q: What kind of compounds change color when bases come into contact with them, so they can be used to detect bases?


Read this paragraph and choose the correct option from the provided answers:

Certain compounds, called indicators, change color when bases come into contact with them, so they can be used to detect bases. An example of an indicator is a compound called litmus. It is placed on small strips of paper that may be red or blue. If you place a few drops of a base on a strip of red litmus paper, the paper will turn blue. You can see this in the Figure below . Litmus isn’t the only detector of bases. Red cabbage juice can also detect bases, as you can see in this video: http://www. youtube. com/watch?v=vrOUdoS2BtQ .

 Choices:

- liquid

- parameters

- metals

- indicators


A:
indicators