understanding concepts\n1. explain how a physical change differs from a chemical change\n2. classify each of…

understanding concepts\n1. explain how a physical change differs from a chemical change\n2. classify each of the following as a physical or a chemical change. explain why\n(a) garbage rotting\n(b) cutting up carrots\n(c) a silver spoon turning black\n(d) making tea from tea leaves\n(e) bleaching a stain\n(f) boiling an egg\n3. during a power failure, blair lit four identical candles. he placed three candles very close together on a table, and one on a different table.

understanding concepts\n1. explain how a physical change differs from a chemical change\n2. classify each of the following as a physical or a chemical change. explain why\n(a) garbage rotting\n(b) cutting up carrots\n(c) a silver spoon turning black\n(d) making tea from tea leaves\n(e) bleaching a stain\n(f) boiling an egg\n3. during a power failure, blair lit four identical candles. he placed three candles very close together on a table, and one on a different table.

Answer

Brief Explanations:

  1. A physical change only alters the physical properties (such as shape, state) of a substance without changing its chemical composition. A chemical change results in the formation of a new substance with different chemical properties through a chemical reaction.

(a) Garbage rotting is a chemical change as bacteria break down organic matter, forming new substances like methane and carbon - dioxide. (b) Cutting up carrots is a physical change as it only changes the shape and size of the carrots, not their chemical composition. (c) A silver spoon turning black is a chemical change. Silver reacts with sulfur - containing compounds in the air to form silver sulfide. (d) Making tea from tea leaves is a physical change. The tea - making process mainly involves dissolving the soluble components of tea leaves in water without changing the chemical nature of the main substances in a fundamental way. (e) Bleaching a stain is a chemical change. Bleach reacts with the colored substances in the stain to break them down into color - less substances. (f) Boiling an egg is a chemical change. The heat causes the proteins in the egg to denature, changing their chemical structure.

Answer:

  1. A physical change doesn't change the substance's chemical composition, while a chemical change forms a new substance.

(a) Chemical change; bacteria break down organic matter to form new substances. (b) Physical change; only changes shape and size. (c) Chemical change; silver reacts with sulfur - containing compounds. (d) Physical change; mainly dissolving soluble components. (e) Chemical change; bleach reacts with colored substances. (f) Chemical change; heat denatures egg proteins.