1 - Periodicity & Melting Points

What block are Group 1 and 2 in?

s block

What do Group 1 and 2 end in?

s¹ or s²

What block are Group 3 - 0 in?

p block

What do Group 3 - 0 end in?

p¹ to p⁶

What block are transition elements in?

d block

What do transition elements end in?

d¹ to d¹⁰

What block are actinides and lanthanides in?

f block

What do actinides and lanthanides end in?

f

What does hydrogen have in common with Group 1?

Forms +1 ions

What makes hydrogen different from Group 1?

Isn’t a metal

Can form -1 ions

Which group is helium often put in?

Group 0

What makes helium different from Group 0?

Not a p block element

What does periodic mean?

Regular

How is the periodic table periodic?

There are repeat patterns across the periods

What is the structure of the Group 1, 2 & 3 elements in Period 3?

Na, Mg, Al

Metals

Giant lattice structures

Lose outer electrons to form ions

What is the structure of the Group 4 element in Period 3?

Si

4 electrons in outer energy level

Forms 4 covalent bonds

Semi-metal

What is the structure of the Group 5, 6 & 7 elements in Period 3?

P, S, Cl

Non-metals

Form ionic/covalent bonds

Molecules as elements - P₄, S₈, Cl₂

What is the structure of the Group 0 element in Period 3?

Ar

Full outer energy level

Unreactive

How does the melting point change across Period 3?

Increases from Na→Mg→Al

Si has highest

P much lower

S slightly higher than P

Cl lower than P

Ar lowest

Why does the melting point increase from Na to Al?

No. of protons increases - greater nuclear charge

Smaller ions

More delocalised electrons - greater attraction to cations

More energy needed to overcome

Why does Si have the highest melting point?

Giant covalent structure

Many strong covalent bonds

More energy needed to overcome

Why is the melting point of P much lower than Si?

Tetrahedral structure - simple molecular

Van der Waals forces

Less energy needed to overcome

Why is the melting point of S slightly higher than P?

Puckered 8 membered ring molecule

Larger molecule

Stronger van der Waals - more electrons

More energy needed to overcome

Why is the melting point of Cl lower than P?

Diatomic molecule

Less van der Waals - less electrons

Less energy needed to overcome

Why does Ar have the lowest boiling point?

Single atoms

Less van der Waals - less electrons

Less energy needed to overcome