2.1 Periodicity Flashcards Preview

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Flashcards in 2.1 Periodicity Deck (31)
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1
Q

In what order are elements arranged in the periodic table

A

Increasing atomic number

2
Q

Period

A

Row of elements

3
Q

Group

A

Column or elements

4
Q

Periodicity

A

The study of repeating trends and patterns in the periodic table

5
Q

Trend in first ionisation energy across a period

A

Increases across the period with a dip between group 2 and 3 and between group 5 and 6

6
Q

First ionisation energy

A

The energy needed to remove one electron from each atom in one mole of gaseous atoms

7
Q

Why does first ionisation energy increase across a period

A
  • nuclear charge increases
  • similar shielding
  • nuclear attraction on outer electron increases
8
Q

Why does atomic radius decrease across the period

A
  • nuclear charge increases
  • same shielding
  • attraction on outer electron increases
9
Q

What are cations like in size relative to their atoms

A

Smaller

10
Q

Why are cations smaller than their atoms

A

Lose electrons and so lose a shell

Same protons attracting fewer electrons

11
Q

What are anions like in size relative to their atoms

A

Larger

12
Q

Why are anions larger than their atoms

A

Gain electrons so same number of protons attracting more electrons

13
Q

Electronegativity

A

The power of an atom to attract the pair of electrons in a covalent bond

14
Q

What is the trend in electronegativity across a period

A

Increase

15
Q

Why does electronegativity increase across a period

A

Number of protons increase
Electrons in same shell- similar shielding

Attraction on outer electrons increases

16
Q

Why is there variation in melting and boiling points across a period

A

Changes in structure and bonding

17
Q

What is the structure in Na, Mg and Al

A

Giant lattice

18
Q

What bonding Na, Mg and Al

A

Metallic

19
Q

Trend in boiling and melting points from Na to Al

A

Increase

20
Q

Why do melting and boiling points increase from Na to Al

A

Metallic bonds increase

Charge increases

More delocalised electrons

Attraction between ions and delocalised electrons increases

21
Q

structure and bonding of silicon

A

giant covalent

22
Q

melting and boiling point of Si

A

v high

23
Q

why does Si have high m and b point

A

huge numbers of strong covalent bonds needed to be broken

24
Q

structure of phosphorus, sulphur and chlorine

A

simple covalent

25
Q

melting/boiling points of sulphur, phosphorus and chlorine

A

relatively low

26
Q

why are melting/boiling points relatively low in phosphorus, sulphur and chlorine

A

weak VDW forces between molecules need to be overcome

27
Q

in what order to boiling/melting points increase in sulphur, phosphorous and chlorine

A

chlorine>phosphorus>sulphur

28
Q

why do boiling points increase from chlorine>phosphorus>sulfur

A

molecules get larger so more electrons involved in bonding- VDWs greater

29
Q

structure of Ar

A

atoms

30
Q

melting/boiling point Ar

A

very low MP/BP

31
Q

why does argon have a low melting/boiling point

A

monoatomic- very weak VDWs between atoms