Avogadro’s number is derived from the number of carbon-12 atoms in 12.00 grams. In a chemical reaction, 3.0 moles of hydrogen react with 4.0 moles of oxygen to produce water. How many reacting molecules are present when the reaction starts? A.
1.8 x 1024 molecules

B.
6.0 x 1023 molecules

C.
4.2 x 1024 molecules

D.
2.4 x 1024 molecules

The diagram below shows the different phase transitions that occur in matter. which arrow represents the transition in which dew is formed?

If we compare and contrast electromagnetic waves with sound waves, all but one statement is true. that is a) sound waves require a medium to travel while electromagnetic waves do not. b) electromagnetic waves can travel through the vacuum of space while sound waves cannot. c) electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere. eliminate d) sound waves must bounce off of matter in order to travel while electromagnetic waves do not require matter to be present.

What term is applied to a scientist who studies ancient life, including animal and plant fossils a. anthropologist b. dendroclimatologist c. geophysicist d. paleontologist