[Maximum number: 1]
The Periodic Table lists all the known elements.
Elements are arranged in order of 1 number.
The melting points of Group I elements 2 down the group.
The melting points of Group VII elements 3 down the group.
Which words correctly complete gaps 1,2 and 3 ?
1
2
3
nucleon
decrease
increase
nucleon
increase
decrease
proton
decrease
increase
proton
increase
decrease