Author: nashton
Company: RM plc

F321 module 2 Practice 5:

1.	High boiling point or difficult to break linked to strong bonds in the right
context within Li or C 	1
Li	conducts by delocalised/free/mobile electrons  structure: giant metallic 	3
or ‘+ ions with a sea of electrons’ for giant mark
C	conducts by delocalised/free/mobile electrons  structure: giant covalent
with layers 	4
N	No mobile charge carriers/electrons/ions to conduct electricity 
simple molecular structure/made of N_2 molecules
low boiling point or easily broken due to	3
intermolecular forces/
van der Waals’ forces 
QWC:	At least 2 complete sentences in which the meaning is clear. 	1
[12]

2.	1s^22s^22p^2 
[1]

3.	CO_2:		correct covalent bonds around carbon 
outer shell electrons correct 
(must be ‘dot AND cross’ or electron source clearly shown
(different coloured for source?)
[2]

4.	correct dot and crosses 
correct charges 
[2]

5.	(i)	Energy change when each atom in 1 mole 
of gaseous atoms 
loses an electron  (to form 1 mole of gaseous 1+ ions).	3
(ii)	increasing nuclear charge/number of protons 
electrons experience greater attraction or pull / atomic
radius decreases / electrons added to same shell /same or
similar shielding 	2
(iii)	In B, electron being removed is at a higher energy /
In Be, electron being removed is at a lower energy 
An s electron is lost in Be AND a p electron is lost in B 	2
[7]

6.	uneven distribution of electrons 
instantaneous /oscillating/changing/temporary/transient/
dipole on one atom 
causes an induced/resultant dipole on another
molecule/atom 
chlorine gas; bromine liquid; iodine solid/
volatility decreases from Cl_2 ® Br_2 ® I_2/
boiling point increases from Cl_2 ® Br_2 ® I_2/
stronger forces are broken from Cl_2 ® Br_2 ® I_2 
number of electrons increases down group 
greater/more van der Waals’ forces / induced dipole-
dipole interactions / forces between the molecules 
[6]

7.	1s^22s^22p^63s^23p^63d^24s^2 
[1]

8.	(i)

positive ions 	electrons 	(must be labelled)	2
(ii)	electrons move 	1
[3]

9.	simple molecular 	2
[2]

10.	(i)	First  ionisation (energy) 	2
Ra(g) ® Ra^+(g) + e^− 
1 mark for equation
1 mark for state symbols
‘-‘ not required on ‘e’	2
(ii)	atomic radii of Ra > atomic radii of Ca/
Ra has electrons in shell further from nucleus than Ca/
Ra has more shells 
Ra has more shielding than Ca 
: ‘more’ is essential
Ra electron held less tightly/less attraction on electron 	3
[7]

The King's CE School