Which is an example of a chemical change? water evaporating from a puddle cloth tearing when pulled wood forming sawdust when cut bread baking in an oven

when cut bread baking in an oven

Explanation: Chemical change is defined as a change in which rearrangement of atoms take place and leads to formation of new substance.

Physical change is defined as a change in which change in shape, size or state of the substance takes place. No new substance is formed.

1. water evaporating from a puddle: involves only a phase change from liquid to gaseous state and no new substances are formed.

2. cloth tearing when pulled: involves only in stretching of fabric and no new substances are formed.

3. wood forming sawdust involves only change in size and shape of wood and no new substances are formed.

4. when cut bread baking in an oven involves oxidation of bread and the sugar gets converted to ethanol and carbon dioxide and thus represents a chemical change.

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.