Which of the following is an example of a chemical change?
25 points
A. water evaporating
B. carbon joining with oxygen to form carbon dioxide
C. ice cream melting
D. salt dissolving into the water to form a solution
A chemical change is one in which the substance CHANGES into another substance. Wavter evaporating still is water. Salt dissolving is still NaCl. Ice cream melting still is ice cream, although it's a liquid now instead of a frozen solid. C joining with oxygen to form carbon dioxide is a chemical change. You're starting with C and end up with something different, namely, carbon dioxide. C initiall and CO2 at the end is an entirely different substance.
I need help
To determine which of the options is an example of a chemical change, we need to understand the difference between a physical change and a chemical change.
A physical change refers to a change in the physical state or appearance of a substance, where no new substances are formed. In contrast, a chemical change involves the formation of new substances with different chemical properties.
Now let's analyze each option to determine which ones are chemical changes:
A. Water evaporating: Water evaporating is a physical change. The liquid water is changing into water vapor, but no new substances are formed. Therefore, this is not an example of a chemical change.
B. Carbon joining with oxygen to form carbon dioxide: This is an example of a chemical change. When carbon (C) combines with oxygen (O₂), it forms a new compound called carbon dioxide (CO₂). This reaction involves the rearrangement of atoms, resulting in the formation of a different substance with different chemical properties.
C. Ice cream melting: Ice cream melting is also a physical change. The solid ice cream changes into liquid form due to an increase in temperature, but no new substances are formed. Hence, this is not an example of a chemical change.
D. Salt dissolving into water to form a solution: Dissolving salt into water is a physical change. The salt crystals separate into individual ions in the water, forming a saltwater solution. However, no new substances are created in the process. Therefore, this is not an example of a chemical change.
Based on the analysis, the only example of a chemical change among the given options is:
B. Carbon joining with oxygen to form carbon dioxide.