Answer:
Heat conductivity: Physical property
Silver tarnishing: chemical change
Sublimation: physical change
Magnetizing steel: physical property
Length of a metal object: physical property
Shortening melting: physical property
exploding dynamite: chemical change
combustible: chemical property
water freezing: physical change
Acid resistance: chemical property
brittleness: physical property
milk souring: chemical change
baking bread: chemical change
Explanation:
First you need to understand the differences between physical and chemical change; physical and chemical property.
<u>Physical properties vs chemical properties:</u>
Physical properties are properties that you can observe without changing the substance's composition. This means you can measure these properties without changing them chemically.
Chemical properties, on the other hand, are properties are not as direct. These properties are generally determined by the way the react with other substances changing their composition.
<u>Physical changes vs chemical changes:</u>
A substance that undergoes physical change does not change in chemical composition. They may look physically different in terms of size and shape, but overall, their chemical composition remains constant. The best example would be water. Water can change phases, from solid to liquid when they melt. Essentially, they look like different substances, but the change is only physical and not chemical.
Chemical change, is different by the fact that they change in chemical composition. Bonds are broken and/or made through the reaction, which changes them not only physically but chemically as well. Some of the most indicative signs of a chemical change occurring are: change in color, odor, production of gas, production of light/heat.