Chemistry Stucture and bonding question

I think the element is Boron which belongs to gr. 3 and therefore has 3 electrons in its outer-most energy level. Chloride of Boron... Hmm, perhaps trichloroborane which has the formula BCl3... I'm not too sure on this so don't go writing anything down, perhaps someone can confirm (or not as the case may be) my idea...

how can u tell its boron?

Ionisation energies explain the existence of sub-shells... Now, examine the ionisation energies for say Hydrogen and Helium, they are both relatively high. This is because an influencing factor which affects ionisation energy is strong, this factor the charge on the nucleus (there are other factors such as electron shielding but I cba to explain)... Because Hydrogen and Helium's outer electrons are very close to the nucleus, they have a strong nucleus pull, therefore more energy is required to remove the electron. Now, the reason why there is a dip in ionisation energy around Boron and Berylium is because of their structures. Now, you need to know about sub-shells. Boron has an electron configuration of 1s22s22px1 - 2p orbitals have higher energies than 2s orbitals. Now if you consider that the outer-most electron of Boron is shielded by the 1s2 and 2s2 electrons, so this reduces the pull from the nucles. You also have to consider that the outer-most electron is further away from the nucleus thus a lessened attraction. All of this results in a lowered ionisation energy. If you don't understand what I have said PM me and I can explain in more detail...

i understand ionisation energies its just that i don't know how u concluded that 786,1580,3230,4360,16000,20000,23600,29100 = boron ? or a grp 3 element

I'm wrong. Boron can only have 6 ionisation energies can't it? Ignore me!

help on the question below plz:

e) an element x has the following successive ionization energies:

786,1580,3230,4360,16000,20000,23600,29100

i) which group does element x belong to?

ii) write down the outer configuration of element x

iii) suggest the formulae for two chlorides of X.


ive done some research but i still need help.

thx beforehand

i) Group 4 - Large jump in ionization energy from Fourth IE to Fifth. (Change in shells causes the larger IE)
ii) Well, It has 4 electrons in its outermost shell.
iii) XCl4, XCl2

I dont think you need to mention the actual Element. I'd refer to it as X since they never asked for the name.