Are the following examples of chemical or physical changes?
Column A
1.
rusting metal:
rusting metal
2.
slicing bread:
slicing bread
3.
corroding battery:
corroding battery
4.
boiling water:
boiling water
Column B
a.chemical change
b.physical change
Column A
1. Corroding metal: a. chemical change
2. Slicing bread: b. physical change
3. Corroding battery: a. chemical change
4. Boiling water: b. physical change
Column A
1. rusting metal: chemical change (a)
2. slicing bread: physical change (b)
3. corroding battery: chemical change (a)
4. boiling water: physical change (b)
To determine whether the given examples are chemical or physical changes, we need to understand the difference between the two.
Chemical change involves a substance undergoing a chemical reaction, resulting in the formation of a new substance with different chemical properties. Physical change, on the other hand, refers to a change that does not alter the chemical composition of a substance. It involves a change in physical properties, such as shape, size, state, or phase.
Now, let's analyze the examples provided:
1. Rusting metal: Rusting metal is a chemical change. It occurs when iron reacts with oxygen and water in the presence of certain catalysts, resulting in the formation of iron oxide (rust). This process involves a chemical reaction and the formation of a new substance.
2. Slicing bread: Slicing bread is a physical change. Although the shape and size of the bread change when sliced, it does not result in a new substance with different chemical properties. The composition of the bread remains the same.
3. Corroding battery: Corroding battery is a chemical change. Battery corrosion is caused by an electrochemical reaction involving the breakdown of the battery's metallic components (such as zinc) in the presence of acid or moisture. This chemical reaction leads to the formation of new substances and a change in the battery's properties.
4. Boiling water: Boiling water is a physical change. When water is heated, it undergoes a phase change from a liquid to a gas, but its chemical composition remains unchanged. The water molecules simply gain enough energy to transition from the liquid phase to the gaseous phase.
Now, let's match the examples with the corresponding category:
Column A
1. Rusting metal: a. chemical change
2. Slicing bread: b. physical change
3. Corroding battery: a. chemical change
4. Boiling water: b. physical change