Chemical And Physical Change

Breaking a plate is a physical change because it does not alter the chemical composition of the plate. The plate remains made of the same material, but it changes in its physical form. The bonds between the molecules of the plate are broken, causing it to shatter into smaller pieces. This change can be reversed by reassembling the pieces, demonstrating that it is a physical change rather than a chemical one.

An object is not changing to another substance.

Melted ice is a physical change because it undergoes a change in state from solid to liquid without any alteration in its chemical composition. In this process, the ice molecules gain enough energy to overcome the forces holding them together in a solid structure, resulting in a transition to a liquid state. The molecules remain the same, only their arrangement changes. Therefore, this change is classified as a physical change rather than a chemical change.

Making chicken stir-fry involves cooking the chicken, which is a chemical change. Chemical changes involve the formation of new substances with different properties. In this case, the heat applied during cooking causes chemical reactions in the chicken, leading to changes in its texture, flavor, and color. Therefore, making chicken stir-fry is a chemical change.

Washing a cup involves cleaning it with water and soap, which does not result in any chemical reaction or change in the composition of the cup. It is simply a physical change where dirt, stains, and other particles are removed from the cup's surface. The cup remains the same chemically before and after washing, making it a physical change.

Cutting hair is a physical change, not a chemical change. Chemical changes involve the formation of new substances with different chemical properties, while physical changes only alter the physical appearance or state of a substance. Cutting hair does not involve any chemical reactions or the formation of new substances, it only changes the length or shape of the hair strands. Therefore, the statement is false.

Cutting is a physical change, not chemical.

A tarnished ring is a chemical change because tarnishing is a result of a chemical reaction between the metal in the ring and substances in the environment, such as oxygen or sulfur. This reaction causes a chemical change in the metal, resulting in the formation of a new compound on the surface of the ring. Unlike a physical change, such as bending or melting, which can be reversed without changing the composition of the substance, tarnishing cannot be easily reversed and involves the formation of new chemical compounds.

Flammability refers to the ability of a substance to burn or ignite. When a substance undergoes a chemical change, its chemical composition is altered, resulting in the formation of new substances with different properties. In the case of flammability, the substance is reacting with oxygen in the air, producing heat and light, and forming new chemical compounds. Therefore, flammability is a chemical change rather than a physical change, which refers to changes in the state or form of matter without altering its chemical composition.

Bacon frying is a chemical change because it involves the process of cooking, which causes the proteins and fats in the bacon to undergo chemical reactions such as denaturation, oxidation, and caramelization. These chemical reactions result in the browning and flavor development of the bacon, transforming its original composition and properties. Therefore, bacon frying is not a reversible change and is classified as a chemical change rather than a physical change.

Something is changing to another substance.

A glowing fire is not a physical change, but rather a chemical change. When a fire glows, it is due to the combustion of fuel, which involves a chemical reaction between the fuel and oxygen. This chemical reaction produces heat, light, and various gases. Therefore, the statement that a glowing fire is a physical change is incorrect.

Curded milk undergoes a chemical change because the proteins in the milk, specifically casein, undergo a process called denaturation. Denaturation occurs when the proteins unfold and form new bonds, resulting in the formation of curds. This process is irreversible and involves a change in the chemical composition of the milk, making it a chemical change rather than a physical change.

Cutting, ice melting, and chewing food are all examples of a physical change.

Smoke rising is a physical change because it involves a change in the physical state or appearance of the substance. In this case, the solid particles in the smoke are being converted into a gas form, which is a physical transformation. The chemical composition of the smoke remains the same, but its physical properties, such as its state and appearance, are altered.