For a reaction to occur, energy must be absorbed to break chemical bonds
<u>Explanation:</u>
Reactions can be classified as chemical reaction, nuclear reaction, thermal reaction. So in these three reaction types, the nature of energy will only be varying.
But in order to execute a reaction, there should be breaking of existing bonds and then formation of new bonds. So for breaking of the bonds of reactants, energy should be absorbed from the surrounding.
Then the extra energy will be released after forming the products. Thus, the process of absorption of energy will lead to endothermic process and the process of releasing of energy will lead to exothermic reaction. So for a reaction to occur, energy must be absorbed to break the chemical bonds.
Answer:
The atmospheric pressure is
.
Explanation:
Given that,
Atmospheric pressure
drop height h'= 27.1 mm
Density of mercury 
We need to calculate the height
Using formula of pressure

Put the value into the formula



We need to calculate the new height




We need to calculate the atmospheric pressure
Using formula of atmospheric pressure

Put the value into the formula


Hence, The atmospheric pressure is
.
You can increase the capacitance of a capacitor by decreasing the plate spacing (A) or by increasing the area of the plates (D).
'A' and 'D' both do the job, so the correct choice is<em> (E)</em> .
Answer:
The magnitude of an earthquake is 5.6.
Explanation:
The magnitude of an earthquake can be found as follows:

Where:
I: is the intensity of the earthquake = 37.25 cm
S: is the intensity of a standard earthquake = 10⁻⁴ cm
Hence, the magnitude is:

Therefore, the magnitude of an earthquake is 5.6.
I hope it helps you!