C2 : The Periodic Table

Question 1

What clue does the period tell us about the element’s electronic structure?

Answer 1

The period number is the same as how many shells it has

Question 2

What clue does the group number tell us about the electronic structure of an element?

Answer 2

The group number is the same as the no. electrons on its outer most shell

Question 3

How did MENDELEEV organise the PERIODIC TABLE?

Answer 3

• IN ventricle columns based on PROPERTIES
• then sorted them HORIZONTALLY - in order of ATOMIC MASS
• he found pattern appear and chemically similar elements naturally fell in same columns
• he left GAPS for elements not yet discovered
• he used trends/properties of the group which had gaps to PREDICT the element fit for the gaps

Question 4

why are NON METALS higher in their group more reactive?

Answer 4

NON METALS REACT BY GAINING ELECTRONS
- upper in group , elements have LESS OUTER SHELLS
- this means closer to nucleus/strong attraction to NUCLEUS
- THIS ATTRACTS MORE ELECTRONS

Question 5

why are GROUP 0 elements so stable and list some of their properties?

Answer 5

• have full outer shell
• UNREACTIVE
• MONATOMIC ( single atom)
• COLOURLESS
• HIGHER MP as go down group bc increase in atom size , so need more energy to overcome intermolecular forces

Question 6

Group 1 properties ?

Answer 6

• soft
• low density/MP
• VERY REACTIVE
• LOWER MP, as move down group due to decreasing attractive forces between electrons and positive ions

Question 7

why does reactivity increase as go down GROUP 1?

Answer 7

• NUMBER OF SHELLS INCREASES as go down group , so further from nucleus
• weaker force of attraction
• less energy needed to overcome force of attraction so electrons EASILY LOST

Question 8

Group 7 properties?

Answer 8

higher mp/bp as go down group
- due to increase of intermolecular forces as atoms become larger, so more energy needed to overcome forces
- REACTIVITY DECREASES as you go down - no. shells increase so less attracted to nucleus , hard to gain electron

Question 9

properties of transition metals?

Answer 9

• compared to alkali metals, transition elements have hIGHER DENISTY/MP
• STRONGER/HARDER
• LESS REACTIVE
  don’t react vigorously with water/air
• important for industrial catalysts
• form coloured compounds