Answers - John Buchan School

(b)Award ONE mark for identifying the process:• melt(ing). 1Do not give credit for:• turns to liquid;• liquefies [this is what happens when gasis compressed];• liquidised/liquidate;• warming,• thaws.(c)Award ONE mark for a description of the mass decreasing:• the mass decreased/got smaller/ went down/got lower/got less/ went small. 1Allow:• it got lighter;• it dropped;• there's a loss of weight.Do not give credit for:• it got shorter.(d)Award ONE mark for an awareness that the products of burning cannot be changed back:• it's a chemical change;• you can't get the wax back;• it changed to a different material.Allow:• you can't re-use a candle after it has burned. 1Do not give credit for:• wax disappears;• the wax turned to a gas;• burning is irreversible [given];• the wax would have melted [this is aphysical change];• the wax has been changed;• it's like baking a cake [not specific].[4]John Buchan Middle School 11