What percentage of the body's bones is made up of water?
a. 22%
b. 25%
c. 73%
d. 83%

In the water cycle , when does water undergo a chemical change

Which scientific design has both practical limitations and limitations due to scale? studying the effect of bleach on the growth of mold spores exposing cultures of duckweed to different intensities of light observing the replication of dna molecules with a hand lens using colored marbles to model a cross between two colors of rabbits

Ascientific idea becomes valid when it is what?