Chemical Vs Physical Change Quiz

A chemical change refers to any change that results in the formation of new substances. This means that the original substances are transformed into different substances with different chemical properties. In a chemical change, bonds between atoms are broken and new bonds are formed, resulting in a chemical reaction. This is different from a physical change, where the substances involved may change in form or state, but their chemical composition remains the same. Weather change and mood change are not related to the formation of new substances and are therefore not considered chemical changes.

Rusting iron undergoes a chemical change. Chemical changes involve the formation of new substances with different chemical properties. In the case of rusting, iron reacts with oxygen and moisture in the air to form iron oxide, which is a different compound with different properties than iron. This process is irreversible and leads to the degradation of the iron over time.

A physical change refers to a change in the physical properties of a substance without altering its chemical composition. Rearranging molecules without affecting the internal structures implies that the molecules are simply being rearranged or reorganized in a different way, but their chemical makeup remains the same. This indicates a physical change rather than a chemical change, as there is no transformation or conversion of the molecules into new substances.

Gasoline burning is not an example of a physical change because it involves a chemical reaction. In a physical change, the substance remains the same, only its physical properties change. However, when gasoline burns, it undergoes a chemical reaction with oxygen, resulting in the formation of new substances like carbon dioxide and water vapor. Therefore, gasoline burning is a chemical change rather than a physical change.

Physical change occurs on the characteristics of shape and size. This means that when a physical change occurs, the shape and/or size of the object or substance is altered, while the chemical composition remains the same. Color, on the other hand, is not a characteristic on which physical change occurs.

When sugar dissolves in water, it undergoes a physical change. This is because the sugar molecules are dispersed and evenly distributed throughout the water, forming a homogeneous mixture. The chemical composition of both sugar and water remains the same, and no new substances are formed. The process of dissolving is reversible, and the sugar can be recovered by evaporating the water. Therefore, the change is considered to be physical rather than chemical, molecular, or nuclear.

Chemical change occurs at the molecular level. During a chemical change, the atoms in a substance rearrange to form new molecules with different properties. This rearrangement involves breaking and forming chemical bonds between atoms, resulting in a new substance. At the molecular level, the individual atoms interact and bond with each other to create the new molecules. Therefore, the correct answer is molecular level.

Chemical change occurs when there is a change in color and texture. Color change is often an indication of a chemical reaction taking place, as different substances can have different colors. Texture change can also occur during a chemical change, as the arrangement of particles may be altered, resulting in a change in the feel or texture of the substance. Both color and texture changes are common indicators of a chemical change occurring.