A rusting bicycle: C - This is a chemical change because the iron in the bicycle reacts with oxygen in the presence of water and forms rust (iron oxide).
Spoiling food: C - Spoiling food involves chemical changes caused by the growth of bacteria, yeasts, or molds that break down the organic matter in the food.
Burning paper: C - Burning paper involves a chemical change where the paper undergoes combustion. It reacts with oxygen, releases heat and light, and forms carbon dioxide and water vapor.
Frying an egg: C - Frying an egg is a chemical change as the proteins in the egg white denature and coagulate when exposed to heat, resulting in a solid structure.
Baking a cake: C - Baking a cake involves various chemical reactions. The ingredients undergo chemical changes due to heat, such as the leavening agents reacting with the acid and moisture to produce carbon dioxide and make the cake rise.
Melting butter: P - Melting butter is a physical change as it changes from a solid to a liquid state due to the increase in temperature. The chemical composition of the butter remains the same.
Write C for chemical change and P for physical change. Give evidence to support your answer.
A rusting bicycle
spoiling food
burning paper
frying an egg
baking a cake
melting butter
3 answers
What do you think the difference is between a physical and chemical change? Be specific with your answer!
The main difference between a physical change and a chemical change is the nature of the changes that occur to the substances involved.
In a physical change, the substance undergoing the change remains the same chemically. The physical properties of the substance, such as its shape, size, phase (solid, liquid, gas), and density, may change, but the chemical composition of the substance remains intact. Physical changes are typically reversible, meaning the substance can be changed back to its original state without undergoing any chemical reactions.
In contrast, a chemical change involves the rearrangement of atoms or molecules in a substance, resulting in the formation of new substances with different chemical properties. During a chemical change, the molecular or atomic composition of the substance is altered, and new chemical bonds are formed or broken. Chemical changes are usually accompanied by the absorption or release of energy in the form of heat, light, or sound.
It is important to note that physical changes do not alter the chemical identity of a substance, while chemical changes result in the formation of different substances with different chemical identities.
In a physical change, the substance undergoing the change remains the same chemically. The physical properties of the substance, such as its shape, size, phase (solid, liquid, gas), and density, may change, but the chemical composition of the substance remains intact. Physical changes are typically reversible, meaning the substance can be changed back to its original state without undergoing any chemical reactions.
In contrast, a chemical change involves the rearrangement of atoms or molecules in a substance, resulting in the formation of new substances with different chemical properties. During a chemical change, the molecular or atomic composition of the substance is altered, and new chemical bonds are formed or broken. Chemical changes are usually accompanied by the absorption or release of energy in the form of heat, light, or sound.
It is important to note that physical changes do not alter the chemical identity of a substance, while chemical changes result in the formation of different substances with different chemical identities.
0 answers