I change color from time to time. Wear me, and I'll tell you your . What am I?

(apex) when a cup of water is dropped, as the cup falls, the water in the cup falls out true or false?

The organism shown is a free-living one that is anchored to the bottom of ponds and streams during one stage of its life cycle what is the common name for the group to which this organism belong

Identify the correct mole ratio for each substance. sodium chloride (nacl) na: cl = 1: ammonium nitrate (nhno) h: o = 4: