Answer: Option (b) is the correct answer.
Explanation:
In a chemical reaction, the bonds between the reactant molecules tend to break leading to the formation of new bonds to produce products.
So, in order to break the bonds between the reactant molecules, energy is required to overcome the attraction between the atoms.
To form new bonds, energy gets released when two atoms come closer to each other. Hence, formation of bond releases energy.
As in the given reaction it is shown that 
< 0, that is, enthalpy change is negative. Hence, energy is released as it is an exothermic process.
Thus, we can conclude that the statement energy released as the bonds in the reactants is broken is greater than the energy absorbed as the bonds in the products are formed, is true about the bond energies in this reaction.
A cone of depression occurs in an aquifer when groundwater is pumped from a well. In an unconfined aquifer, this is an actual depression of the water levels. In confined aquifers, the cone of depression is a reduction in the pressure head surrounding the pumped well.
Answer : The correct option is, (a) Synthesis
Explanation :
Synthesis reaction : A chemical reaction where multiple substances or reactants combine to form a single product.
It is represented as,
Combustion reaction : A chemical reaction in which a hydrocarbon react with the oxygen to give product as carbon dioxide and water.
It is represented as,
Single replacement reaction : A chemical reaction in which the more reactive element replace the less reactive element.
It is represented as,
In this reaction, A is more reactive element and B is less reactive element.
Double replacement reaction : It is a type of chemical reaction where a positive cation and a negative anion of two reactants exchange places to form two new products.
It is represented as,
(X and A are the cations, Y and B are the anions)
The given reaction is, 
In this reaction, calcium combine with the chloride to form calcium chloride as a product.
Hence, the given type of reaction is a synthesis reaction.
Answer:
beta
Explanation:
A beta particle (symbol β) is a high-speed and high-energy electron which is emitted by radioactive decay of the atomic nucleus during process of the beta decay.
Strontium-90 is material which is most commonly used to produce the beta particles.
Beta particles are used to treat conditions such as eye as well as bone cancer.
Answer:
P₅O₁₂
<em>Explanation: </em>
Assume that you have 100 g of the compound.
Then you have 44.7 g P and 55.3 g O.
1. Calculate the <em>moles</em> of each atom
Moles of P = 44.7 × 1/30.97 = 1.443 mol Al
Moles of O = 55.3 × 1/16.00 = 3.456 mol O
2. Calculate the <em>molar ratios</em>.
P: 1.443/1.443 = 1
O: 3.456/1.443 = 2.395
3. Multiply by a number to make the ratio close to an integer
P: 5 × 1 = 5
O: 5 × 2.395 = 11.97
3. Determine the <em>empirical formula
</em>
Round off all numbers to the closest integer.
P: 5
O: 12
The empirical formula is <em>P₅O₁₂</em>.
