Density：練習問題

Mercury is a very dense liquid with a density of \(13.6\text{ g/cm}^3\). Which of the following substances will sink if placed in a container of mercury?

A metal block has a mass of \(156\text{ g}\) and a volume of \(20\text{ cm}^3\). What is its density?

A beaker with a mass of \(150\text{ g}\) contains \(200\text{ cm}^3\) of water (density \(1.0\text{ g/cm}^3\)). A metal alloy is submerged in the water, and the water level rises to \(240\text{ cm}^3\). The total mass of the beaker and its contents is now \(600\text{ g}\). What is the density of the alloy?

A metal cube has a mass of \(540 g\) and a volume of \(60 cm^3\) . What is its density?

When a liquid is heated, its volume usually increases while its mass remains unchanged. Based on this, what happens to the density of the liquid?

Using the particle theory, describe the relationship between the density of a substance and the spacing between its particles when the substance changes from a liquid state to a gaseous state.

A fixed mass of gas is moved from a container with a volume of \(10\text{ m}^3\) into a smaller container with a volume of \(4\text{ m}^3\). Describe and explain the change in the density of the gas.

Explain why saltwater is denser than pure water by using the particle theory to describe how salt particles and water particles are arranged in a solution.

A student has a solid block with a mass of \(240\text{ g}\) and dimensions of \(4\text{ cm} \times 5\text{ cm} \times 6\text{ cm}\).

(a) Calculate the volume of the block in \(\text{cm}^3\).
(b) Calculate the density of the block in \(\text{g/cm}^3\).
(c) If the density of water is \(1.0\text{ g/cm}^3\), determine whether the block will float or sink in water. Briefly explain your reason.

A science student performs an experiment to determine the density of a liquid and its effect on a solid object.

(a) The student measures the mass of an empty beaker as \( 50\text{ g} \). After adding \( 100\text{ cm}^3 \) of a specific oil, the combined mass of the beaker and the oil is \( 142\text{ g} \). Calculate the density of the oil in \( \text{g/cm}^3 \). (2 points)

(b) A small wooden bead with a mass of \( 4.8\text{ g} \) and a volume of \( 6\text{ cm}^3 \) is dropped into the oil. Calculate the density of the bead and predict whether it will float or sink in the oil. (2 points)

(c) According to the particle theory, explain why the density of the oil would decrease if it were heated to a higher temperature. (2 points)