1. C - glass breaking: When glass breaks, the bonds between the molecules are broken, resulting in a rearrangement of the atoms within the glass. This is a chemical change.
2. C - a rusting bicycle: Rust is formed when iron reacts with oxygen in the presence of water. This chemical reaction results in the formation of iron oxide, which is the rust on the bicycle.
3. C - spoiling food: Spoiling food involves the growth of bacteria or fungi, which break down the organic matter in the food. This is a chemical change.
4. C - burning paper: Burning paper involves a chemical reaction with oxygen, resulting in the release of heat, light, and smoke. The cellulose in the paper is broken down into carbon dioxide and water vapor.
5. C - frying an egg: When an egg is fried, the proteins within the egg undergo a chemical change as they denature and coagulate due to the heat. This causes the egg to solidify and change its texture and color.
6. C - baking a cake: The process of baking a cake involves several chemical reactions, such as the leavening agents reacting with acids to release carbon dioxide, which helps the cake to rise. Additionally, the heat causes the proteins, starches, and fats in the cake ingredients to undergo various chemical changes, resulting in a cooked and finished cake.
7. P - melting butter: Melting butter is a physical change because it involves a change in state from solid to liquid. The chemical composition of the butter does not change during melting.
Write C for chemical change and P for physical change. Give evidence to support your answer.
1. glass breaking
2. a rusting bicycle
3. spoiling food
4. burning paper
5. frying an egg
6. baking a cake
7. melting butter
3 answers
In 6 sentences, what do you think the difference is between a physical and chemical change? Be specific with your answer!
Physical changes involve a transformation in the physical properties of a substance, such as its shape, size, or state, without altering its chemical composition. In physical changes, the substance still retains its original identity and can be reverted back to its original form. An example of a physical change is when ice melts into water. The ice undergoes a change in state from a solid to a liquid, but its chemical composition remains the same.
On the other hand, chemical changes result in the formation or breaking of chemical bonds, leading to a change in the chemical composition of a substance. Chemical changes are characterized by the formation of new substances with different properties than the original substances. An example of a chemical change is when iron rusts in the presence of oxygen and moisture. The iron reacts with oxygen to form iron oxide (rust), resulting in a change in both the physical and chemical properties of the substance.
In summary, physical changes involve alterations in the physical properties of a substance without changing its chemical composition, while chemical changes involve the formation or breaking of chemical bonds, resulting in a change in the chemical composition of a substance.
On the other hand, chemical changes result in the formation or breaking of chemical bonds, leading to a change in the chemical composition of a substance. Chemical changes are characterized by the formation of new substances with different properties than the original substances. An example of a chemical change is when iron rusts in the presence of oxygen and moisture. The iron reacts with oxygen to form iron oxide (rust), resulting in a change in both the physical and chemical properties of the substance.
In summary, physical changes involve alterations in the physical properties of a substance without changing its chemical composition, while chemical changes involve the formation or breaking of chemical bonds, resulting in a change in the chemical composition of a substance.
0 answers