I've been doing some past papers for chemistry and this was one of the questions, the mark scheme doesn't offer a picture so naturally I don't know if I'm correct or not. Could someone willing please draw it out for me? Thanks very much.
I'm not sure where your blue electron came from, I drew this, I think it's the same?
EDIT: Apologies for the very scruffy writing.
EDIT2: After looking at it again, my OH bonds wouldn't have a negative charge...I think I understand now. The electron from Ca pairs with the oxygen and the other electron of oxygen bonds with hydrogen. But that wouldn't have a negative charge? Arghh, confused.
I'm not sure where your blue electron came from, I drew this, I think it's the same?
EDIT: Apologies for the very scruffy writing.
EDIT2: After looking at it again, my OH bonds wouldn't have a negative charge...I think I understand now. The electron from Ca pairs with the oxygen and the other electron of oxygen bonds with hydrogen. But that wouldn't have a negative charge? Arghh, confused.
I think its because there are 3 different types of atom's (Ca, H and O), hence, you must indicate that they have distinct electrons.
Edexcel isn't really picky. Other examining boards such as AQA and OCR can be at times.
BTW nice use of Colour
Thanks
I would be that picky
Woody
Yeah, thanks. I do understand the blue part now, but I'm rather confused on the edited areas
Okay in ionic compounds metals donate electrons to non-metals, so the outer two electrons of calcium have been donated to the OH's, hence they have 1 blue electron and a negative charge each. This leaves Ca with a 2+ charge and a full outer shell.
Oxygen has six electrons (red) + 1 from Ca (blue) and is sharing one of it's electrons with the hydrogens (green). Hope that helps
yeh but they ask you to draw a 'dot and cross diagram' not a ' 3 different colour dots diagram', so what would be the best way to answer this question?