Rusting nails

This task is about planning a fair test.
Jayden wanted to find out if nails rust more quickly in salt water than in fresh water.
He decided to put one nail in salt water and one in fresh water to find out what happened. He knew that if he wanted this to be a fair test it was important to change only one thing and keep everything else the same. (In science these things are called variables).

Question 1Change answer

a)  For planning a fair test to find out whether nails rust more quickly in salt water or fresh water,
     which things would you need to keep the same?
     Show this on the chart below by selecting yes or no.
Sort of water yesno
Amount of water yesno
Time nails are in the water yesno
Type of nail yesno

Question Change answer

b)  Highlight one thing in each box in the chart below so Jayden knows exactly what he needs to do to set up a fair test. The first one has been done for you.
  • Nail 1
  • Nail 2
Planning for a fair test. Question: Will nails rust more quickly in fresh water or salt water?
 
Nail 1 Nail 2
Steel nail
Copper nail
Steel nail
Copper nail
Fresh water
Salt water
Fresh water 
Salt water
100ml (metal is partially covered) 
500ml (metal is fully covered)
100ml (metal is partially covered) 
500ml (metal is fully covered)
1 week
2 weeks
1 week
2 weeks
Published on Assessment Resource Banks (https://arbs.nzcer.org.nz)