Which of the following is an example of a physical change?(1 point) choices
boiling an egg boiling an egg dissolving sugar in water dissolving sugar in water burning a match burning a match cooking a hamburger
To determine which of the given choices is an example of a physical change, we need to understand what a physical change entails. A physical change is a change in the form or state of matter, where no new substances are formed. In other words, the chemical makeup of the materials involved remains the same.
Now, let's analyze each choice:
1. Boiling an egg: When you boil an egg, the liquid egg white and yolk solidify, and the state of matter changes from liquid to solid. This is a physical change.
2. Dissolving sugar in water: When you dissolve sugar in water, the sugar molecules spread out and become dispersed in the water, forming a homogeneous mixture. There is no new substance formed, only a physical dispersion of the sugar molecules within the water. Therefore, this is also a physical change.
3. Burning a match: Burning a match involves a chemical reaction where the matchstick combines with the oxygen in the air, releasing heat and light and forming new substances such as ash and smoke. This is a chemical change, not a physical change.
4. Cooking a hamburger: Cooking a hamburger involves various chemical reactions, including the denaturation of proteins and the Maillard reaction, which causes browning and the formation of new flavors and aromas. The changes in color, texture, and taste in the cooking process are a result of chemical changes, making this a chemical change.
Based on the explanations above, the examples of physical changes among the given choices are boiling an egg and dissolving sugar in water.