1) she said it has a higher electronegativity. Electronegativity - affinity of an atom to attract a bonded pair of electrons in a covalent bond. Electron density - you will see it in organic chemistry, in the bonding of benzene and alkenes (describes how close the electrons are). For example, pi bonds in alkene have an electron density above and below the sigma bond between the 2 carbons.
2) Yes that is correct. Chlorine is more electronegative than hydrogen, so it pulls the ‘electron cloud’ (you can imagine it like that to remember it)
3) Electronegativity - is dependent on atomic radius and nuclear charge. The smaller the atomic radius, the stronger the attraction (less electron shielding). The stronger the nuclear charge, the greater the attraction.
So it goes up and across to the right of the periodic table (fluorine being the most polar). We dont count the noble gases as they dont normally form bonds.
4) COOH is a weak acid so partially dissociates in aqueous solution… COOH -> COO- + H+.
I dont understand what you mean by COOH dissociating and ‘chloride pulls the negative charge because it is not electronegative thus making the bond stronger?’
Read
https://www.chemguide.co.uk/atoms/bonding/electroneg.htmlWhen I was studying A Level chemistry, our teacher recommended chemguide. It has a nice 2000’s feel of a website
Although it had knowledge beyond A Level as well which was nice.
If you learnt about electron orbitals than consider this:
Carbon has electron configuration of 1s^2 2s^2 2p^2
In the second shell, carbon has 2 unpaired electrons (in the p orbitals). But you learnt to form a bond - 2 orbitals must overlap, each containing 1 electron. So how does carbon form 4 bonds, when it has 2 unpaired electrons? It is knowledge beyond A Level but it is nice to know (your teacher may touch on promotion in organic chemistry, with alkane and alkene. Our teacher did it with ethene, when we learnt about pi bonds)
https://www.chemguide.co.uk/basicorg/bonding/methane.html