2.1 Periodicity Flashcards
1
Q
What is the definition of periodicity?
A
- Pattern in properties across a row which is repeated in each row
2
Q
What is the trend in atomic radius across a period?
A
- Shielding is negligible
- Proton number increases
- FOrce of attraction between nucleus and outer electrons increases
- Radius decreases
3
Q
What is the general trend in first ionisation energy across a period?
A
- Increases
- More protons
- Atomic radius decreases
- Shielding is negligible
4
Q
What is the general trend of electro negativity across a period?
A
- Increases
- More protons
- Shielding is negligible
- Smaller atomic radius
- Nucleus is more able to attract a covalent bond
5
Q
Why does melting point increase between sodium and aluminium?
A
- Al has higher charge
- Al has more delocalised electrons
- Smaller ions
6
Q
Why do giant covalent structures have such high melting points?
A
Have to break many strong covalent bonds
7
Q
Why does Barium Chloride need to be acidified when testing for sulphates?
A
Both sulfates and sulfites produce a white precipitate but sulfites are soluble in acids so it avoids confusion
