u can refer to periodic table for ans.

lithium chloride:
lithium is in grp I, same as sodium & potassium.
symbol for lithium is Li
just like sodium (Na) in grp I,
the +ve ion for lithium chloride is Li⁺

fluoride, chloride, bromide & iodide are known as halides. they r in grp VII & grp VII elements are known as halogens.
grp VII is next to grp VIII or grp 0, so halides r more likely to be -ve ions.
since VII is 1 less than VIII, the charge is -1.
hence chloride is Cl⁻.


from above, u can figure out the +ve & -ve ions for lithium bromide, sodium fluoride & potassium iodide



iron(II) sulfate:
iron ions can be +2 charged or +3 charged (bcos it is a transition metal)

as the name above implied, we know this is iron(II) or the ion is +2 charged
hence, Fe²⁺


sulfate ion is a standard SO₄²⁻.
this is knowledge.
there is a why for it, may be TMI for u, but not necessary for u at Sec 3.



calcium oxide:
calcium is in grp II.
its ion is +ve charge.
hence, Ca²⁺

oxygen is in grp VI
its ion is -ve charge.
since VI is 2 less than VIII
the -ve ion for oxide is O²⁻



lead(II) carbonate:
lead ions can be +2 charged or +4 charged (bcos it is a transition metal)

as the name above implied, we know this is lead(II) or the ion is +2 charged
hence, Pb²⁺


carbonate ion is a standard CO₃²⁻.
this is knowledge.
there is a why for it, may be TMI for u, but not necessary for u at Sec 3.




copper(II) sulfate:
copper ions can be +1 charged or +2 charged (bcos it is a transition metal)

as the name above implied, we know this is copper(II) or the ion is +2 charged
hence, Cu²⁺


u know sulfate above




sodium hydroxide:
sodium is in grp I,
what do u think is the +ve ion ?

hydroxide ion is a standard OH⁻.
this is knowledge.
there is a why for it, may be TMI for u, but not necessary for u at Sec 3.



silver nitrate:
silver is more complex bcos it is a transition metal and amphoteric.
it can have an oxidation state of -2, -1, +1, +2 or +3.
u can google abt it but it may be TMI for u.
impt thing is +1 charge is the most stable for silver.
hence, Ag⁺

nitrate ion is a standard NO₃⁻.
this is knowledge.
there is a why for it, may be TMI for u, but not necessary for u at Sec 3.



ammonium hydroxide:
ammonium hydroxide is one of the alkalis u can find ur chem lab, alongside sodium hydroxide & potassium hydroxide.
so ammonium hydroxide is quite similar to sodium hydroxide.


ammonium ion is a standard NH₄⁺.
this is knowledge.
there is a why for it, may be TMI for u, but not necessary for u at Sec 3.


u know hydroxide ion above


mercury symbol is Hg

what do u think mercury(II) oxide contains?

mercury ( II ) oxide contains Hg^2+ , is it ?

Yuo, (II) denotes a charge of 2+.

Let me know if you need me to pen this down on paper. It's a very similar approach to your previous post (probably coming from the same worksheet).

u mentioned:
" mercury ( II ) oxide contains Hg^2+ , is it ? "

gd job!
u r getting the hang of it

.

@eric nicholas k
yup , is it possible for u to pen it down & show me ? thank you so much !

Will attempt some around 2 am tonight.