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.
Answer:
moving i think! Hope this helps
Explanation:
First question. Applying ideal gas equation PV=nRT, P= 101.3 x 10³Pa = 1atm. therefore, 1 x 260 x 10^-3 = n x 0.082 x 294.( Temperature in kelvin=273+21). n = 0.01 moles. Volume of gas at STP= n x 22.4 = 0.01x22.4 = 0.224L. Hope this helps
Length of 1 side 1.2*10^-5km =1.2*10^-5*10^5 =1.2cm
<span>volume of the cube (1.2)^3=1.728 cm^3 </span>
<span>density= mass/volume= 1.1/1.728=0.636 g/cm^3</span>
The question is incomplete.
You need two additional data:
1) the original volume
2) what solution you added to change the volume.
This is a molarity problem, so remember molarity definition and formula:
M = n / V in liters: number of moles per liter of solution
To give you the key to answer this kind of questions, supppose the original volumen was 1 ml and that you added only water (solvent).
The original solution was:
V= 1 ml
M = 0.2 M
Using the formula for molarity, M = n / V
n = M×V = 0.2 M × (1 / 10000)l = 0.0002 moles
For the final solution:
n = 0.0002 moles
M = 0.04
From M = n / V ⇒ V = n / M = 0.002 moles / 0.04 M = 0.05 l
Change to ml ⇒ 0.05 l × 1000 ml / l = 50 ml. This would be the answer for the hypothetical problem that I assumed for you.
I hope this gives you all the cues you need to answer similar problems about molarity.
