Question

Absent-minded Alfred put down a bottle containing silver on the table. When he went to retrieve it, he realized he had forgotten to label the bottle. Unfortunately, there were two full bottles of the same size side-by-side. Alfred realized he had placed a bottle of mercury on the same table last week. State two ways Alfred can determine which bottle contains silver without opening the bottles.

Short answer

Weigh the bottles or check their electrical conductivity.

Step-by-step solution

Weigh the Bottles

Since silver and mercury have different densities, weigh both bottles. The one with the higher mass given identical volume will contain mercury, as mercury (with a density of approximately 13.6 g/cm³) is denser than silver (with a density of approximately 10.5 g/cm³).

Check for Electrical Conductivity

Use a conductivity meter to check if the bottles conduct electricity. Silver is an excellent conductor of electricity, while mercury is only a fair conductor. The bottle that shows a higher conductivity will contain silver.

Key concepts

density comparison

Density is a measure of how much mass is contained in a given volume. Different substances have different densities. This property is very useful for identifying materials. In the case of the bottles with either silver or mercury, Alfred can compare their densities to identify them. Silver has a density of approximately 10.5 grams per cubic centimeter (g/cm³). Mercury, on the other hand, is denser, with a density of about 13.6 g/cm³.

To determine which bottle contains mercury and which contains silver, Alfred can weigh both bottles. Since the bottles are of the same size (volume), the one with the greater mass has the denser substance, which is mercury. The lighter bottle, for the same size, will contain the less dense silver. This method is straightforward and does not require opening the bottles.

electrical conductivity

Electrical conductivity is the ability of a substance to conduct electrical current. Conductivity depends mainly on the nature of the material and its structure. Metals are generally good conductors because of the free electrons that move easily through their lattice structures.

Silver is one of the best electrical conductors. It allows electric current to pass through it with minimal resistance. Using a conductivity meter, Alfred can measure how well each bottle conducts electricity. The bottle with higher electrical conductivity contains silver.

Mercury also conducts electricity, but it is not as efficient as silver. Thus, the bottle with lower conductivity will have mercury. This method is non-invasive and provides a quick and reliable way to differentiate between the two metals.

silver properties

Silver is a precious metal known for several unique properties. It is highly reflective, which makes it useful in mirrors and coatings. Its best-known use is in jewelry and coins due to its luster and rarity.

One of the most notable properties of silver is its excellent electrical conductivity. It is the best conductor among all metals, even better than copper. This makes it highly valuable in electrical and electronic applications, such as in conductors, connectors, and circuits.

Additionally, silver has a relatively high density of 10.5 g/cm³. However, compared to mercury, it is less dense. This density difference is a key factor in identifying bottles containing silver versus mercury.

mercury properties

Mercury is unique among metals because it is liquid at room temperature. This property makes it useful in thermometers, barometers, and other scientific instruments.

Mercury is also notable for its high density, approximately 13.6 g/cm³. This is higher than most other common metals, including silver. This high density helps in distinguishing it from other substances like silver, simply by weighing.

While mercury can conduct electricity, it is not as efficient as other metals like silver. Its conductivity is sufficient for making electrical switches and relays but not for high-conductivity applications. Being aware of these properties can help in understanding the differences between mercury and silver, aiding in their identification in various scenarios.