<u>Answer:</u>
<u>For a:</u> The wavelength of light is 
<u>For b:</u> The light is getting absorbed
<u>Explanation:</u>
To calculate the wavelength of light, we use Rydberg's Equation:

Where,
= Wavelength of radiation
= Rydberg's Constant = 
= Higher energy level = 7
= Lower energy level = 3
Putting the values in above equation, we get:

Hence, the wavelength of light is 
There are two ways in which electrons can transition between energy levels:
- <u>Absorption spectra:</u> This type of spectra is seen when an electron jumps from lower energy level to higher energy level. In this process, energy is absorbed.
- <u>Emission spectra:</u> This type of spectra is seen when an electron jumps from higher energy level to lower energy level. In this process, energy is released in the form of photons.
As, the electron jumps from lower energy level to higher energy level. The wavelength is getting absorbed.
Taking into account the definition of density, assuming all other conditions remain the same, increasing mass will cause an object's density to increase.
Density is defined as the property that matter, whether solid, liquid or gas, has to compress into a given space. That is, density is a quantity referred to the amount of mass contained in a given volume.
Density is an intensive property since it does not vary with the amount of substance.
Since density is the relationship between the mass and the volume of a substance, its calculation is defined as the quotient between the mass of a body and the volume it occupies:

In the previous expression it can be observed that the density is inversely proportional to the volume: the smaller the volume occupied by a certain mass, the greater the density.
On the other hand, density is directly proportional to mass: the greater the mass, the greater the density.
Finally, assuming all other conditions remain the same, increasing mass will cause an object's density to increase.
Learn more about density:
Answer: It means that the energy is being stored or preserved to be used at a later time.
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Answer:
1L of hot water just below the Boling point
Explanation:
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