Basically, the P-P chain turns 4 protons into: 1 neutrino, 1 gamma ray, 1 positron, 1 helium nucleus.
A gamma ray = energy.
The chain converts hydrogen into helium and makes energy.
This is all occurring through fusion reactions where 2 protons basically smash into each other. But, it could also be e.g. a proton smashing with a deuterium nucleus. Or, other nuclei smashing together to make something else.
Hope this helps!
Erosion by either wind or/and water from lack of plant roots holding the soil together which will eventually lead to desertification.
Since water is polar, and these molecules are nonpolar, they don't exactly interact in anyway.
Since they can't interact, when you pour any of those elements in a recipient with water, you can clearly see both liquids and they don't mix.
Hope it helped, BioTeacher101
A Compound
Explanation: a compound is when 2 or more chemical elements are chemically bonded together. Hope this helps!