Preliminary Idea Essay

2410 WordsApr 4, 201310 Pages
Dear Students, Please delete the portions of your notes highlighted in red and add in the parts highlighted in green Given two charged particles, the magnitude of the electrostatic force one exerts on another is 1) proportional to the charge on the particle. A greater charge leads to a stronger force. 2) inversely proportional to the size of the particle. i.e. given the same charge and distance apart, a smaller particle would exert a greater force on another particle 3) inversely proportional to the distance apart. The further 2 charged particles are, the weaker the force they exert on one another. 1.1.1 Charge Density Putting points 1) and 2) together, we actually arrive at how the strength of electrostatic force is affected by a property known as the charge density. Charge density is defined as the quantity of charge per unit volume of space of a charged particle. We can also simplify it by saying it is proportional to the charge of the particle and inversely proportional to its radius assuming it is a sphere. A particle with greater charge density exerts a greater electrostatic force on other charged particles. 1.2 Electronegativity In the previous chapter, you learnt about effective nuclear charge, which is the nett force experienced by the outermost electrons of an atom. However, in that chapter we only looked at what happens if the atom is alone. In reality, the electrostatic force due to the effective nuclear charge of the atom extends beyond the outermost electron. When 2 atoms are in proximity, the nucleus of each atom exerts an attractive force on its own electrons as well as the electrons of the other atom and also a repulsive force on the nucleus of the other atom. There is a nett attractive force on the electrons of the other atom. So how do we know how strongly each atom attracts the electron of another atom? Electronegativity is a concept introduced by