Answer:
b. It exists in three different states at normal conditions in the Earth's atmosphere
Explanation:=
Snow, rain and water vapour can exist at normal conditions in the Earth's atmosphere.
a. is wrong. Only hydrogen and helium can escape Earth's atmosphere in significant amounts.
c. is wrong. The molecules of every substance are in motion even when it is solid.
d. is wrong. Other substances can form from a wide range of chemical processes.
e. is wrong. All substances expand when they become a gas.
1,2-dimbromopropane would be something like C which is the second best answer.
B would be correct if it had another carbon.
A is like C but incorrect for the same reason. 1,2-dibromoethane is what A is.
The answer has to be D where the bromines are right across from each other.
Answer: 14 Explanation: Mass number: the total number of protons and neutrons in a nucleus.
Mass number = Protons + Neutrons
=
6
+
8
=
14
The central ,innermost or most essential part of something
