I believe the answer is D. The atmosphere, different layers of the atmosphere can help in different ways! The stratosphere helps protect us from the sun's rays; The Mesophere is what helps protect us from meteorites! It's so cold that they burn up in that area.
Answer:
Even though the two substances possess many similarities, they have some unique properties. In turn, since they have the same properties, if they were the same substance, it would make matters worse, if the same chemical was in two different places, there would not be a difference between them since they are the same, just as it is with are two different chemicals would have differing properties since they are two properties would vary from one another since they are 2 totally different things!
Answer: 
Explanation:
A single displacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution. Thus one element should be different from another element.
Synthesis reaction is defined as the reaction where substances combine in their elemental state to form a single compound.
Decomposition reaction is defined as the reaction where a single substance breaks down into two or more simpler substances.
Combustion is a type of chemical reaction in which hydrocarbons burn in the presence of oxygen to form carbon dioxide and water along with heat.
The existence of an atom was first suggested by Democritus, the idea is then developed in 1803 by John Dalton.
According to Dalton's atomic theory, matter is made up of atoms which are inseparable and can not be destroyed further. For a given element, all atoms have identical mass and properties. Atoms of two different elements combine to form compounds and rearrangement of these atoms results in chemical reaction.
