B. a combustion reaction involves a hydrocarbon burning with oxygen gas to produce water and carbon dioxide.
C. this is an endothermic reaction since ΔH would be positive.
3. I am pretty sure it is referring to the activation energy which is a characteristic all chemical reaction have and in a combustion reaction the spark gets the reaction over the activation energy.
4. K₂O(s)+CO₂(g)⇒K₂CO₃(s)+energy
The energy level of the reactants is higher than the energy level of the products (you can see this with energy diagrams).
5. 2HgO(s)+energy⇒2Hg(l)+O₂(g)
the energy levels of the products is higher than the energy level of the reactants. (this can also be seen with energy diagrams)
Answer:
The reaction only takes place if the reactants are in contact, then the surface exposed is very important because as the exposed surface of the reactants increases, the reaction velocity also increases. If the lumps are not broken up, a big amount of baking soda would be only available to react after the surrounding soda has already reacted.
Helium has only 2 electrons in it's valence shell
So, option D is your answer.
Hope this helps!
Answer:
1000m3
Explanation:
12000=mass*gravity, considerinh gravity 10
12000=mass*10 then mass=1200Kg
With density 1.2Kg/m3
1.2Kg ... 1m3
1200Kg ... 1000m3
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