Periodicty

Question 1

What bonds/forces need to be broken to melt elements across a period?

Answer 1

Metallic bonds strong electrostatic attraction between the positive metal ions and negative delocalised electrons
Giant covalent- strong electrostatic attraction between a shared pair of electrons and the nuclei of bonded atom
Rest-Van Der Waals

Question 2

Explain the trend in melting points across a period?

Answer 2

First three relatively high mp but () has even higher melting point as it has covalent bonds which are stronger so more energy needed to overcome
Last 4-no pattern van Der walls dependent on number of electrons varies

Question 3

Explain why Al has a higher mp than mg and Na

Answer 3

More highly charged cations attracting more delocalised electrons so a stronger attraction more energy needed to overcome

Question 4

State and explain what happens to atomic radius across a period

Answer 4

Decrease the number of protons in the Nucleus increases by one each time and electrons added placed in same shell-no extra shielding from another shell
Increases attraction

Question 5

Why is there a difference in energy between the second and third element?

Answer 5

The highest energy electron in… Is in a ….s sublevel. In … It’s in a …p sublevel which is higher in energy so less needed to remove it

Question 6

How does the trend in conductivity change across a period?

Answer 6

First 3 elements-good conductivity (metallic bonding) delocalised electrons to carry the charge
The rest of the elements don’t conduct:
Silicon-giant covalent so has no delocalised electrons and rest have simple covalent structures so have no free electrons or ions

Question 7

Why is the Al better than Mg and Na?

Answer 7

More electrons in outer shell so more delocalised electrons to carry the charge

Question 8

What does periodicity mean?

Answer 8

The property is repeated the trend is repeated in different periods of the table

Question 9

Explain the variations FIE across a period

Answer 9

One more proton each time 
The atomic radius decreases 
Similar electron shielding 
More attraction between nucleus and electrons 
Higher FIE

Question 10

Why is there an increase In FIE between fifth and sixth elements?

Answer 10

In an … Atom the …p electrons are in separate orbitals. In an … Atom the highest energy electron is paired in an orbital with an electron of the opposite spin. Repulsion between these two causes a decrease the FIE