Why can't elements be separated into smaller parts using chemical means? Too much energy is required, since you'd have to break them down into protons, neutrons, and electrons. You can get this much energy together with nuclear reactions, but not by chemical means.
The complete question is as follows: How many moles of a gas at 100 c does it take to fill a 1.00 l flask to a pressure of 152kPa
Answer: There are 0.0489 moles of a gas at 
is required to fill a 1.00 l flask to a pressure of 152kPa.
Explanation:
Given: Volume = 1.00 L,
Pressure = 152 kPa (1 kPa = 1000 Pa) = 152000 Pa
Convert Pa into atm as follows.
Temperature = 
Using the ideal gas formula as follows.
PV = nRT
where,
P = pressure
V = volume
n = no. of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.
Thus, we can conclude that there are 0.0489 moles of a gas at is required to fill a 1.00 l flask to a pressure of 152kPa.
2n² rule:
This rule is used to determine number of electrons in particular shell.
n=1 means K shell
n=2 means L shell
n=3 means M shell
n=4means N shell
The first K shell can hold upto 2 electrons, L shell can hold up to 8, third M shell can hold up to 18and the fourth N shell can hold upto 32 electrons. This rule of arrangement of electrons according to the shell is known 2n2 rule where n means number of shell.
For example: There is one proton in the nucleus of hydrogen atom, which moves in K shell path. It has no neutron.
