4. A
because PbCl2 is an ionic compound and it's solid, so it's a substance.
It cannot be mixture, because it's a pure molecule.
5. D
despite that both substances are gases, colorless they are different molecules, so they should have different either chemical and physical properties
6. C
this substance made from W atoms and others are made from molecules
B. a circle graph
circle graphs are the best to show percentages because they’re very easy to look at and get info from
Answer:
D.
Explanation:
Although all of these answers are similar, it seems that all three are the answer. I am sorry if the answer ends up being B but I'm pretty sure the answer is D. Charles Darwin's evolution theory "evolved", get it, from the natural selection theory. The theory is described as "the process whereby organisms better adapted to their environment tend to survive and produce more offspring." However, some factors that effect natural selection are competition, selection and variation. I believe all three fit the answer and therefore I believe answer D is correct.
The answer is for this question is c