If I pour the water off after I boil the banana, what separating technique is this?
A. Decantation
B. Distillation
C. Hand Picking
D. Magnetism
The correct answer and explanation is:
Correct Answer: A. Decantation
Explanation:
Decantation is a simple method used to separate mixtures, typically involving a liquid and solid or two immiscible liquids, based on differences in density. In this process, the liquid is carefully poured off from the top, leaving behind the denser substance or residue.
When boiling a banana, the banana and water form a mixture where the solid banana parts settle or remain heavier at the bottom or are suspended in the water. After boiling, if you pour off the water and leave the boiled banana behind, you are using the method of decantation. This technique works because water is a liquid and can flow easily when poured, while the solid banana chunks do not flow with the same ease and are thus left behind in the container.
This process does not involve any change in the chemical structure of the substances, nor does it require any advanced equipment. It is based purely on physical separation. Decantation is frequently used in kitchens, laboratories, and industries where the removal of liquid from solid residues or less dense liquids is needed.
To clarify why the other options are incorrect:
- Distillation involves boiling a liquid to create vapor and then condensing it back to liquid, separating substances based on boiling points. It is not applicable here because no vapor condensation is involved when pouring off water.
- Hand picking is used to separate visibly different solids, not solids from liquids.
- Magnetism is used when one component of the mixture is magnetic, such as iron filings in sand, which does not apply to bananas and water.
Therefore, pouring water off after boiling a banana is a clear example of decantation.