When the charged balloon is brought near the wall, it repels some of the negatively charged electrons in that part of the wall. Therefore, that part of the wall is left repelled.
<u>Explanation</u>:
- Balloons don't stick to walls. However, if you rub the balloon on an appropriate piece of material such as clothing or a wall, electrons are pulled from the other material to the balloon.
- The balloon now as more electrons than normal and therefore has an overall negative charge. Two balloons like this will repel each other.
- The other material now has an overall positive charge. Because opposite charges attract, the balloon will now appear to stick to the other material. If you didn't rub the balloon first, it's charge would be neutral and it wouldn't stick to the wall.
4 Quantum numbers are used
1.Azimuthal
2.Principal
3.Spin
4.Magnetic
Given :
A certain compound contains 4.0 g of calcium and 7.1 g of chlorine.
Its relative molecular mass is 111.
To Find :
Its empirical and molecular formulas.
Solution :
Moles of calcium , 
.
Moles of chlorine , 
.
The ratio calcium and chlorine is 1 : 2 .
So , the empirical formula is 
.
Now , molecular mass of is :
So , 
Therefore , the molecular formula is also .
Hence , this is the required solution .
Have a high suface area to volume ratio
To know the electrostatic force between two charges or between two ions, you can use the Coulomb's Law. The equation is F = k*q1*q1/r^2, where F is the electrostatic force, q1 and q2 are the charger for Na and Cl, and r is the distance between the centers of both atoms. In literature, the distance is 0.5 nm or 0.5 x 10^-9 meters. The charge for Na+ and Cl- is the same magnitude but different in sign. Since Na+ is a cation, its charge is +1.603x10^-19 C (the charge of an electron). For Cl- being an anion, its charge is -1.603x10^-19 C. The constant k is an empirical value equal to 9x10^9. Using the formula:
F = (9x10^9)(+1.603x10^-19)(-1.603x10^-19)/(0.5 x 10^-9)^2
F = -9.25 x 10^-10 Newtons
The negative denotes that the net force is more towards the Cl- ion.
