D will because water just turns from liquid to a gas by adding heat. That is a physical change. The other equations are chemical changes.
The molecular element describes the amount of protons, neutrons, and electrons found in an atom
An atomic element is the subject in the formula such as ... sulfur, carbon, or oxygen
The answer is intermediate, so E.
2n² rule:
This rule is used to determine number of electrons in particular shell.
n=1 means K shell
n=2 means L shell
n=3 means M shell
n=4means N shell
The first K shell can hold upto 2 electrons, L shell can hold up to 8, third M shell can hold up to 18and the fourth N shell can hold upto 32 electrons. This rule of arrangement of electrons according to the shell is known 2n2 rule where n means number of shell.
For example: There is one proton in the nucleus of hydrogen atom, which moves in K shell path. It has no neutron.
Answer:
KBr
Explanation
KBr is an ionic compound which have very high BP since they exist as 3D crystals
Methyl Bromide, CH3Br. is a covalent compound which have low BP since they exist as individual molecules