<u>Answer:</u> The wavelength of spectral line is 656 nm
<u>Explanation:</u>
To calculate the wavelength of light, we use Rydberg's Equation:

Where,
= Wavelength of radiation
= Rydberg's Constant = 
= Final energy level = 2
= Initial energy level = 3
Putting the values in above equation, we get:

Converting this into nanometers, we use the conversion factor:

So, 
Hence, the wavelength of spectral line is 656 nm
Answer:
the melting point of aluminum is 660 degrees Celsius.
D would be your best bet because evaporation occurs when water is heated, it then vibrates and then magic!
Answer:
Approximately
, assuming that this gas is an ideal gas.
Explanation:
Look up the standard room temperature and pressure:
and
.
The question states that the volume of this gas is
.
Convert the unit of all three measures to standard units:
.
.
.
Look up the ideal gas constant in the corresponding units:
.
Let
denote the number of moles of this gas in that
. By the ideal gas law, if this gas is an ideal gas, then the following equation would hold:
.
Rearrange this equation and solve for
:
.
In other words, there is approximately
of this gas in that
.