English and History but I'm dropping them next year and doing AH's in the others.
How about you?
This year I took English(Nat 5), Maths, Chemistry, Human Biology and Physics
I was going to take AH Maths, Chemistry and Biology next year... Well, after the disastrous maths exam this morning and the terrible human biology exam last week, I'm not sure to be honest :/
Guys give me tips please...is it a wise idea to simply do past papers for chemistry or should i go over the whole course then do it i havent done many past papers before...maybe only 1 or 2
Guys give me tips please...is it a wise idea to simply do past papers for chemistry or should i go over the whole course then do it i havent done many past papers before...maybe only 1 or 2
For sciences I would always say it's best just to go over as many past papers as possible. If you see yourself struggling with a particular topic during the past papers then note it down and revise it. Also it may be worth going over your PPA's. Nevertheless, if you've got the time to spare then it wouldn't hurt to look over some course notes.
Guys give me tips please...is it a wise idea to simply do past papers for chemistry or should i go over the whole course then do it i havent done many past papers before...maybe only 1 or 2
In chemistry there's a limited number of questions they can ask, so i would recommend doing past papers.
For sciences I would always say it's best just to go over as many past papers as possible. If you see yourself struggling with a particular topic during the past papers then note it down and revise it. Also it may be worth going over your PPA's. Nevertheless, if you've got the time to spare then it wouldn't hurt to look over some course notes.
can someone explain these 2 questions, i have either forgotten or i'm just stupid or both lol
1) It tells you what isoelectronic means (same electron arrangement). So which option has two elements in it with the same electron arrangement as each other?
2) NaCl - 0.6 mol of Chloride ions. ration of Na:Cl is 1:1 so there are 0.6 mol of Na ions
Na2SO4 - 0.2 mol of sulphate ions. ratio of Na: SO4 is 2:1 so there are 0.4 mol of Na ions
1) It tells you what isoelectronic means (same electron arrangement). So which option has two elements in it with the same electron arrangement as each other?
2) NaCl - 0.6 mol of Chloride ions. ration of Na:Cl is 1:1 so there are 0.6 mol of Na ions
Na2SO4 - 0.2 mol of sulphate ions. ratio of Na: SO4 is 2:1 so there are 0.4 mol of Na ions
0.6 + 0.4 = 1 so D
Thanks! but for 1 none matched up, unless im doing it wrong :/
Thanks! but for 1 none matched up, unless im doing it wrong :/
Remember that to become an ion an atom must either lose or gain electrons depending on its arrangement. So if one atom had an arrangement of 2,8,7 then it's ion would have an arrangement of 2,8,8 If another had an arrangement of 2,8,8,1 then it's ion would have an arrangement of 2,8,8 too, and they would be isoelectronic
It can't be A or B because you need to balance the equation and it can't be C because you can't have more water molecules than hydrogen ions.
Wait I would have said B. You put 3 H20 on the right to balance the 3 O on the left and then put 6 H on the left to balance the 6 H you added on the right. I'm pretty sure that's how we were taught how to do it unless I'm missing something?