test to show the rate of water (may be coloured) uptake in a blackboard chalk

Question 1

1.

Answer 1

fill a Petri dish with a depth of 1cm or (coloured) water and place the blackboard chalk inside upright

Question 2

2.

Answer 2

use a stopwatch to meatier the time

use a pin or a marker to mark on the chalk the height of the ink stain and use a ruler to measure in mm every 1 min

Question 3

3.

Answer 3

record results in a suitable table and plot a graph of height of ink stain against the time

Question 4

4.

Answer 4

the rate of water uptake is the gradient of the graph