Compound are formed by two or more elements chemically combined. For example: H^2O is the water formula, this is a compound because you two elements which are Hydrogen and Oxygen and together they form a compound. The (^2) is the amount of atoms the formula has, in this case Hydrogen has two atoms and Oxygen is neutral.
<span>When you have to balance an equation it means that you have to balance both parts of equation so that the numbers of each elements will have the same amount. According to this rule, it is quite easy to distinguish unbalanced reaction, and the answer is a) HBr + Ca(OH)2 → CaBr2 + H2O as you can see that amount of oxygen on both sides is not the same.</span>
Answer:
B: increase.
Explanation:
When we are considering two gases A and B in a container at room temperature .
We have to find the change on rate of reaction when the number of molecules of gases A is doubled
Let [A]=a and [B]=b
A+B
product
Rate of reaction
![R_1=k[A][B]=kab](https://tex.z-dn.net/?f=R_1%3Dk%5BA%5D%5BB%5D%3Dkab)
We know that concentration is increases with increase in number of moles
When the number of molecules of gases A is doubled then concentration of gases A increases.
Therefore ,[A]=2a
Rate of reaction


Hence, the rate of reaction is 2 times the initial rate of reaction.Therefore, the rate of reaction will increase when the number of molecules of gases A is doubled.
Answer: B: increase.
Gets exited and moves at a faster constant speed