A student investigated what happens when metal carbonates are heated. Metal carbonate 1/30 Limewater -Stop clock The student: . used the apparatus to investigate heating four metal started the stop carbonates clock at the same time as he began to heat the metal carbonate stopped the stop clock when carbon dioxide was produced. The student's results are shown in the table. Metal carbonate Calcium carbonate Copper carbonate Magnesium carbonate Zinc carbonate Tick (v) Time taken for the production of carbon dioxide to start in seconds 163 24 92 67 the type of graph the student should draw from these results. Type of graph Bar chart Line graph Scatter graph Tick () . . (i)