Chemical Changes And Structures-Trends In The Periodic Table (Page 2 of 3) in pdf

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4. The bar chart shows the melting points of chlorides of elements 3 to 20

(with no bars for 10, 15 and 18).

Melting

Points of

Chlorides

(

a) In general what happens to the melting point of the chloride as the Group Number

increases

b) Explain why no values are given for elements 10 and 18.

c) From the bar chart, state which of the chlorides has the weakest forces between

the molecules.

d) Predict a value for the melting point of the chloride of element 15.

5. (a) Lithium starts the second period of the Periodic Table.

Describe and explain the trend in electronegativity values across this period from Li to F?

(b) Explain why the third ionisation energy of magnesium (7750 kJ mol-1) is so much

greater than the third ionisation energy of aluminium (2760 kJ mol-1).

electronegativity. (you may wish to use a data booklet.)

i phosphorus or carbon

ii) silicon or nitrogen

Chemical Changes And Structures-Trends In The Periodic Table Page 2