Answer: decomposition
Explanation:
1 . Combustion is a type of chemical reaction in which a hydrocarbon reacts with oxygen to form carbon dioxide ans water along with liberation of large amount of energy.
2. Decomposition is a type of chemical reaction in which a single reactant gives two or more than two products.

3. Single replacement is a type of chemical reaction in which a more reactive element displaces the less reactive element from its slat solution.
4. Synthesis is a type of chemical reaction in which two or more than two reactants combine together to give a single product.
The more UV rays reach the earth
Answer:
The partial pressure of oxygen in the mixture is 296 mmHg.
Explanation:
The pressure exerted by a particular gas in a mixture is known as its partial pressure. So, Dalton's law states that the total pressure of a gas mixture is equal to the sum of the pressures that each gas would exert if it were alone.
This relationship is due to the assumption that there are no attractive forces between the gases.
So, in this case, the total pressure is:
PT=Phelium + Pnitrogen + Poxygen
You know:
- PT= 756 mmHg
- Phelium= 122 mmHg
- Pnitrogen= 338 mmHg
- Poxygen= ?
Replacing:
756 mmHg= 122 mmHg + 338 mmHg + Poxygen
Solving:
756 mmHg - 122 mmHg - 338 mmHg = Poxygen
Poxygen= 296 mmHg
<u><em>The partial pressure of oxygen in the mixture is 296 mmHg.</em></u>
Answer:
element
Explanation:
we know that helium is a pure substance although helium atoms are sometimes mixed with their isotopes it is still the same element. since there is no other element combined with helium this makes it an element.