Answer:
The main difference between asteroids and comets is their composition, as in, what they are made of. Asteroids are made up of metals and rocky material, while comets are made up of ice, dust and rocky material. Both asteroids and comets were formed early in the history of the solar system about 4.5 billion years ago.
Explanation:
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Answer:
U --> Th + He
Explanation:
Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number less than 2 as compared to parent atom the starting atom.
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴
Answer:
The answer to your question is: the third option is correct.
Explanation:
"Alkenes" ________.
are reasonably soluble in water This option is incorrect, alkenes are insoluble in water.
are relatively polar compounds This option is wrong, alkenes are not polar molecules.
have lower boiling points than alcohols of similar molecular weight This option is true, alkenes have a lower boiling point than alcohols.
both have lower boiling points than alcohols of similar molecular weight and are relatively polar compounds. This option is incorrect because is combining true with false facts.
The answer is waterspouts
Combustion:
The saturated hydrocarbons are relatively inert except at high temperatures. Combustion is one of the more important chemical reactions of the alkanes.
Alkanes have the general formula of CnH2n+2. For example, an alkane with 6 carbon atoms (n = 6) would have a formula of C6H2·6+2 or C6H14. Structurally C6H14 would be shown as: