Top answers

Draw the structure, name the shape and show bond angles of the molecules XeF4 and SbF4-. In your answer explain why each structure is different, despite both having a central atom, surrounded by 4 fluorine atoms.

Xe is in group 8, the noble gases. Therefore it has 8 electrons in its outer shell. Fluorine atoms have 7 electrons, yet one is an unpaired electron, so this is the electron in fluorine that gets involved in...
GJ
Answered by George J. • Chemistry tutor
25917 Views

Core 1 question: Draw the graph "y = 12 - x - x^2"

I always found drawing graphs one of the hardest parts of maths - especially in C1 where you cannot use a calculator to help you. So, I used some simple rules to find key parts of the graph which would simpl...
TH
Answered by Tess H. • Maths tutor
8489 Views

What was the process of the Meelson and Stahl experiment in proving the process of DNA replication?

The double helix structure of DNA was already proven by X-Ray diffraction, but the process of replication was still unknown There were 3 possible mechanisms: conservative, semi-conservative and dispersive PR...
AJ
Answered by Aran J. • Biology tutor
3515 Views

Solve x^2 > |5x - 6|

We need to split the problem into two cases to remove the abs sign. Case 1: 5x - 6 >= 0, equivalent to x >= 6/5. In this case the problem is now to find the values of x that satisfy x 2 > 5x - 6. Re...
JH
Answered by James H. • Maths tutor
4648 Views

There are 300 students at a school who have been asked to attend assembly. 1/10 students are sat on chairs, 85% of students are sat on the floor, the rest do not attend assembly. How many students did not attend assembly?

300 x 1/10 = (300/10) x 1 = 30 students sat on chairs 85% of 300 = (300/10) x 8.5 = (30 x 8) + (30 x 0.5) = 240 + 15 = 255 students sat on the floor Students who did not attend = 300 - 30 - 255 = 15
JD
Answered by Jonny D. • Maths tutor
4151 Views