Measuring pH of common substances

Depending on the pH substances can be acidic or basic. Traditionally those solutions that tasted sour were said to be acidic and solutions that tasted bitter and were slippery to touch were said to be basic. We are going to use indicators to know if a substance is acid o alkali. An indicator contains a chemical that changes color when it comes in contact with acids or bases. For example litmus and universal indicator papers turn red in strong acids and blue in strong bases. let's see how we are doing!!

WATER FLEAS

Have you heard about water fleas?
 They are also called Daphnia and are an order of crustaceans who are so named because they tend to swim by making little jumps. Water fleas are small, between 0.2 and 3 mm in length and found in most freshwater habitats.
Some are kept as live food for aquarium fishes, or as interesting creatures to study because their bodies are almost transparent.

Daphnia from maisanjose

They have not been easy to observe as they move very fast and suddenly change their position!! For you to see how they move...