Question

tell the odd one out and give a reason why it's odd

1.iron,copper,silver,silicon

2.helium,neon,argon,magnesium

3.oxygen,hydrogen,phosphorus,silver

4.copper,iron,lead,mercury,sodium

5.ammonium ion,sulphate ion,chlorine ion,nitrate ion

Answer 1

The first one is odd as every other option contains a fluid except of the first choice

Answer 2

5 one because it is ion and all are not