Answer:
(A) first order reaction
Explanation:
A first order reaction is a type of reaction in which the rate of the reaction depends only on the concentration on one of the reactants. Since A is the only reactant we have, it is right to deduce that this reaction is a first order reaction.
Note: while the order of this reaction is 1, its molecularity is 2. The molecularity of a reaction is the number of moles of reactants that is actually reacting.
(B) is wrong
This is because a zero order reaction is one in which the rate of reaction is not influenced by the concentrations of the reactants and hence remains constant irrespective. Since we were not furnished with this idea in the question, it is only right that we reject this answer.
(C) is wrong.
C is outrightly wrong as we have only one reactant.
(D) is wrong
We have only one reactant.
Answer: 16700 Joules
Explanation:
The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

Q = Heat absorbed = ?
m = mass of sand = 2 kg
c = heat capacity = 
Initial temperature =
= 
Final temperature=
= 
Change in temperature ,
Putting in the values, we get:


16700 J of energy must be added to a 2-kilogram pile of it to increase its temperature from 40°C to 50°C
Answer:
For the most part radish seed growth is best when they are planted in cool soil; early spring or fall are the preferred seasons for many varieties. Next, be sure to get the soil in good shape before planting – loose, full of seasoned organic material, but not overly fertile. Moisture and soil depth must be right, too.
Explanation: