Write a paragraph answering the questions and use your knowledge about evidence of a chemical change and physical change. What are different examples of chemical changes that occur in the world around us? Can physical and chemical changes occur at the same time? Provide an example explaining your thinking. Draw a conclusion and make a claim. What do these reactions say about substances and chemical reactions that would hold true in most cases?
Use evidence to support your analysis and conclusion.
Explain your analysis and conclusion.
There are numerous examples of chemical changes occurring in the world around us. For instance, when wood burns in a fire, it undergoes a chemical change as it reacts with oxygen in the air to produce carbon dioxide and water vapor. Additionally, the process of oxidation that causes rust on metal is another example of a chemical change. Yes, physical and chemical changes can occur at the same time. One example is when a candle burns. The physical change of the candle melting and the chemical change of combustion happen together. This is evident as the candle wax physically melts while it chemically reacts with oxygen to produce carbon dioxide and water vapor. From these examples, it can be concluded that substances undergo chemical changes when they interact with other substances, resulting in the formation of new substances with different properties. This conclusion is supported by the evidence of the wood burning and rusting metal, where the original substances are transformed into new substances.
finish these sentences to describe the work you did in this portfolio.
One thing that was hard for me was ________________. ________________ helped me to better understand ________________. I think I need more practice with ________________.
One thing that was hard for me was understanding the difference between physical and chemical changes initially. However, conducting research and analyzing examples helped me to better understand the distinction between the two types of changes. I think I need more practice with identifying evidence of chemical changes in everyday scenarios and connecting them to the underlying chemical reactions.
Different examples of chemical changes that occur in the world around us include combustion, oxidation, digestion, and rusting. Combustion refers to the burning of substances, such as when wood is lit on fire. Oxidation occurs when a substance reacts with oxygen, leading to the formation of new chemical compounds, like when an apple turns brown after being exposed to air. Digestion is a chemical change that happens in our bodies when food is broken down into smaller molecules with the help of enzymes. Rusting is another common chemical change where iron reacts with oxygen and moisture in the air, resulting in the formation of iron oxide (rust).
Physical and chemical changes can indeed occur at the same time. For example, when we cook food, both physical and chemical changes take place. The heat from cooking causes physical changes, such as changes in texture, color, and state (solid to liquid, for example). At the same time, chemical changes occur as the ingredients undergo reactions, like proteins denaturing, carbohydrates caramelizing, and fats sizzling.
Based on these reactions, we can conclude that substances have unique properties and can undergo different types of changes depending on the conditions they are exposed to. Chemical reactions involve the rearrangement of atoms and the formation of new substances with different properties. Physical changes, on the other hand, do not result in the formation of new substances and only involve changes in physical properties like size, shape, or state. These observations can generally hold true in most cases, although there may be some exceptions depending on specific situations and substances involved.
In conclusion, evidence from various chemical changes, such as combustion, oxidation, digestion, and rusting, supports the notion that substances can undergo chemical reactions resulting in the formation of new compounds. Additionally, physical and chemical changes can occur simultaneously, as seen in cooking processes. This understanding of substances and chemical reactions allows us to predict and explain many phenomena observed in the world around us.