density & scientific notation practice

A block of aluminum occupies a volume of 15.0 mL and weighs 40.5 g. What is its density?

• 4.5 g/mL

• 2.7 g/mL

• 1.5 g/mL

• 3.0 g/mL

Answer explanation

Density is calculated using the formula: density = mass/volume. Here, density = 40.5 g / 15.0 mL = 2.7 g/mL. Thus, the correct answer is 2.7 g/mL.

A sample of copper has a mass of 89.6 g and a volume of 10.0 mL. What is the density of copper?

• 0.89 g/mL

• 9.86 g/mL

• 8.96 g/mL

• 7.96 g/mL

Answer explanation

Density is calculated using the formula density = mass/volume. Here, density = 89.6 g / 10.0 mL = 8.96 g/mL. Therefore, the correct answer is 8.96 g/mL.

If a liquid has a density of 1.25 g/mL and a volume of 20.0 mL, what is its mass?

• 25.0 g

• 16.0 g

• 28.0 g

• 15.0 g

Answer explanation

To find the mass, use the formula: mass = density × volume. Here, mass = 1.25 g/mL × 20.0 mL = 25.0 g. Therefore, the correct answer is 25.0 g.

A rock weighs 120 g and displaces 40 mL of water. What is the density of the rock?

• 1.5 g/mL

• 3.0 g/mL

• 2.0 g/mL

• 4.0 g/mL

Answer explanation

Density is calculated as mass divided by volume. Here, the rock's mass is 120 g and it displaces 40 mL of water. Thus, density = 120 g / 40 mL = 3.0 g/mL, which is the correct answer.

What is the density of water?

• 1.0 g/mL

• 2.0 g/mL

• 3.0 g/mL

• 5.0 g/mL

Answer explanation

The density of water is commonly accepted as 1.0 g/mL at 4°C. This value is crucial in various scientific calculations and is the standard reference for density measurements.

Tags

NGSS.HS-ESS2-5

A graduated cylinder is filled with water to a level of 20.0 ml. When a piece of aluminum is lowered

into the cylinder, the water level rises to 55.0 ml. If the piece of aluminum has a mass of 15.3 g, what is the density of the aluminum?

• 0.437 g/ml

• 0.912 g/ml

• 1.02 g/ml

• 0.273 g/ml

Answer explanation

To find the density of aluminum, first calculate the volume displaced: 55.0 ml - 20.0 ml = 35.0 ml. Density = mass/volume = 15.3 g / 35.0 ml = 0.437 g/ml. Thus, the correct answer is 0.437 g/ml.

What is the volume of a piece of metal that has a mass of 3.5 g and a density of 1.75 g/ml.

• 2 ml

• 4.5 ml

• 3 ml

• 1 ml

Answer explanation

To find the volume, use the formula: Volume = Mass / Density. Here, Volume = 3.5 g / 1.75 g/ml = 2 ml. Thus, the correct answer is 2 ml.

Using the density of metals provided what would an unknown metal with a mass of 5.0g and a volume of 2.2 ml be classified based on the densities provided.

steel = 2.27 g/ml

aluminum = 2.7 g/ml

copper = 8.96 g/ml

lead = 11.34 g/ml

• aluminum

• copper

• steel

• lead

Answer explanation

To find the density of the unknown metal, divide its mass (5.0g) by its volume (2.2ml), resulting in approximately 2.27 g/ml. This matches the density of steel, classifying the unknown metal as steel.

• 1.20 × 10^4

• 1.23 × 10^4

• 1.30 × 10^3

• 2.0 × 10^4

Answer explanation

To add the numbers, align them by their powers of ten: 1.0 × 10^4 + 2.3 × 10^3 = 1.0 × 10^4 + 0.23 × 10^4 = 1.23 × 10^4. Thus, the correct answer is 1.23 × 10^4.

• -1.08x10^3

• -9.00x10^2

• -1.2x10^3

• -9.50x10^2

Answer explanation

To solve 2.2×10^2 - 1.3×10^3, convert to the same power of ten: 2.2×10^2 = 0.22×10^3. Now, calculate 0.22×10^3 - 1.3×10^3 = -1.08×10^3. Thus, the correct answer is -1.08×10^3.