Density of Water | Chapter 3: Density (2023)

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Lesson 3.3

Key Concepts

  • Just like solids, liquids also have their own characteristic density.
  • The volume of a liquid can be measured directly with a graduated cylinder.
  • The molecules of different liquids have different size and mass.
  • The mass and size of the molecules in a liquid and how closely they are packed together determine the density of the liquid.
  • Just like a solid, the density of a liquid equals the mass of the liquid divided by its volume; D = m/v.
  • The density of water is 1 gram per cubic centimeter.
  • The density of a substance is the same regardless of the size of the sample.

Summary

Students measure the volume and mass of water to determine its density. Then they measure the mass of different volumes of water and discover that the density is always the same. Students make a graph of the relationship between the volume and the mass of water.

Objective

Students will be able to measure the volume and mass of water and calculate its density. Students will be able to explain that since any volume of water always has the same density, at a given temperature, that density is a characteristic property of water.

Evaluation

Download the student activity sheet, and distribute one per student when specified in the activity. The activity sheet will serve as the “Evaluate” component of each 5-E lesson plan.

Safety

Make sure you and your students wear properly fitting goggles.

Materials for Each Group

  • Graduated cylinder, 100 ml
  • Water
  • Balance that measures in grams (able to measure over 100 g)
  • Dropper

Materials for the Demonstration

  • Water
  • Two identical buckets or large containers
  1. Engage

    Do a demonstration to introduce the idea that water has density.

    Materials

    • Water
    • Two identical buckets or large containers

    Teacher preparation

    Half-fill one bucket and add only about 1 cup of water to the other.

    Procedure

    • Select a student to lift both buckets of water.
    • Ask the student volunteer which bucket appears to have more mass.

    Expected results

    The bucket containing more water has more mass.

    Ask students:

    In lessons 3.1—What is Density? and 3.2—The Water Displacement Method, you found the density of solids, by measuring their mass and volume. Do you think a liquid, like water can have a density?
    Students should realize that water has volume and mass. Because D=m/v, water must also have density.
    How do you think you can find the density of a liquid like water?
    Students are not expected to be able to fully answer this question at this point. It is meant as a lead-in to the investigation. But students may realize that they should somehow find the mass and volume of the water first.
    Could both the small and large amounts of water your classmate lifted have the same density?
    Students may point out that the bucket with more water has more mass but a greater volume. The bucket with less mass has less volume. So it is possible that different amounts of water could have the same density.

    Give each student an activity sheet.

    Students will record their observations and answer questions about the activity on the activity sheet. The Explain It with Atoms and Molecules and Take It Further sections of the activity sheet will either be completed as a class, in groups, or individually depending on your instructions. Look at the teacher version of the activity sheet to find the questions and answers.

  2. Explore

    Discuss with students how to find the volume and mass of water.

    Tell students that they are going to try to find the density of water.

    Ask students:

    What two things do you need to know in order to find the density of water?
    Students should realize that they need both the volume and mass of a sample of water to find its density.
    How can you measure a volume of water?
    Suggest that students use a graduated cylinder to measure volume in milliliters. Remind students that each milliliter equals 1 cm3.
    Density of Water | Chapter 3: Density (1)
    How can you measure the mass of water?
    Suggest that students use a balance to measure the mass in grams. Tell students that they can find mass by weighing the water. However, since water is a liquid, it needs to be in some sort of container. So in order to weigh the water, they have to weigh the container, too. Explain to students that they will have to subtract the mass of an empty graduated cylinder from the mass of the cylinder and water to get the mass of just the water.
    Density of Water | Chapter 3: Density (2)
  3. Have students find the mass of different volumes of water to show that the density of water does not depend on the size of the sample.

    Question to investigate

    Do different amounts of water have the same density?

    Materials for each group

    • Graduated cylinder, 100 mL
    • Water
    • Balance that measures in grams (able to measure over 100 g)
    • Dropper

    Procedure

    1. Find the mass of an empty graduated cylinder. Record the mass in grams in the chart on the activity sheet.
    2. Pour 100 mL of water into the graduated cylinder. Try to be as accurate as possible by checking that the meniscus is right at the 100-mL mark. Use a dropper to add or remove small amounts of water.

      Density of Water | Chapter 3: Density (3)
    3. Weigh the graduated cylinder with the water in it. Record the mass in grams.
    4. Find the mass of only the water by subtracting the mass of the empty graduated cylinder. Record the mass of 100 mL of water in the chart.
    5. Use the mass and volume of the water to calculate density. Record the density in g/cm3 in the chart.
    6. Pour off water until you have 50 mL of water in the graduated cylinder. If you accidentally pour out a little too much, add water until you get as close as you can to 50 mL.
    7. Find the mass of 50 mL of water. Record the mass in the activity sheet. Calculate and record the density.

      (Video) How To Calculate Density - With Examples

      Density of Water | Chapter 3: Density (4)
    8. Next, pour off water until you have 25 mL of water in the graduated cylinder. Find the mass of 25 mL of water and record it in the chart. Calculate and record the density.
    Table 1. Finding the density of different volumes of water.
    Volume of water100 mililiters50 mililiters25 mililiters
    Mass of graduated cylinder + water (g)
    Mass of empty graduated cylinder (g)
    Mass of water (g)
    Density of water (g/cm3)

    Expected results

    The density of water should be close to 1 g/cm3. This is true for 100, 50, or 25 mL.

    Ask students:

    Look at your values for density in your chart. Does the density of the different volumes of water seem to be about the same?
    Help students see that most of the different values for density are near 1 g/cm3. They may wonder why their values are not all exactly 1 g/cm3. One reason could be inaccuracies in measuring. Another reason is that the density of water changes with temperature. Water is most dense at 4 °C and at that temperature has a density of 1 g/cm3. At room temperature, around 20–25 °C, the density is about 0.99 g/cm3.
    What is the density of water in g/cm3?
    Students answers will vary, but their values should mostly be around 1 g/cm3.
  4. Have students graph their results.

    Help students make a graph of the data on their activity sheet. The x-axis should be volume and the y-axis should be mass.

    When students plot their data, there should be a straight line showing that as volume increases, mass increases by the same amount.

    Density of Water | Chapter 3: Density (5)
  5. Discuss student observations, data, and graphs.

    Ask students:

    Use your graph to find the mass of 40 mL of water. What is the density of this volume of water?
    The mass of 40 mL of water is 40 grams. Since D = m/v and mL = cm3, the density of water is 1 g/cm3.
    Choose a volume between 1 and 100 mL. Use your graph to find the mass. What is the density of this volume of water?
    Whether students weigh 100, 50, 25 mL or any other amount, the density of water will always be 1 g/cm3.

    Tell students that density is a characteristic property of a substance. This means that the density of a substance is the same regardless of the size of the sample.

    Ask students:

    Is density a characteristic property of water? How do you know?
    Density is a characteristic property of water because the density of any sample of water (at the same temperature) is always the same. The density is 1 g/cm3.
  6. Explore

    Explain why the density of any size sample of water is always the same.

    Project the image Density of Water.

    Water molecules all have the same mass and size. Water molecules are also packed pretty close together. They are packed the same way throughout an entire sample of water. So, if a volume of water has a certain mass, twice the volume will have twice the mass, three times the volume has three times the mass, etc. No matter what size sample of water you measure, the relationship between the mass and volume will always be the same. Because D=m/v, the density is the same for any amount of water.

    (Video) Density - Why does oil float on water? | #aumsum #kids #science #education #children

    Project the animation Liquid Water.

    Water molecules are always moving. But on the average they are packed the same throughout. Therefore, the ratio between the mass and volume is the same, making the density the same. This is true no matter the size of the sample or where you select your sample from.

  7. Extend

    Have students consider whether the density of a large piece of a solid substance is the same as the density of a smaller piece.

    Give students time to calculate the density of each of the three samples drawn on their activity sheet and answer the related questions.

    Density of Water | Chapter 3: Density (6)

    Ask students:

    The density of a liquid is the same no matter what the size of the sample. Could this be true for solids, too? Calculate the density of each of the three samples to find out.
    Yes. The density of a solid substance is the same no matter how big or small the sample.
    Sample A has a mass of 200 g. What is the density of Sample A?
    • D = m/v
    • D = 200g/100cm3
    • D = 2 g/cm3
    If you cut Sample A in half and looked at only one half, you would have Sample B. What is the density of Sample B?
    If students do not know what the mass is, tell them that it is half the mass of Sample A. Because Sample A was 200 g, Sample B is one half the volume and therefore one half the mass (100 g).
    • D = m/v
    • D = 100g/50 cm3
    • D = 2 g/cm3
    If you cut Sample B in half you would have Sample C. What is the density of Sample C?
    • D = m/v
    • D = 50g/25 cm3
    • D = 2 g/cm3
(Video) Form 3 Physics | Chapter 3 | Casharka 1aad | Density | Manhajka Cusub

Standards

  • NGSS Lesson 3.3

    for this lesson

  • CCELA Lesson 3.3

    for this lesson

Student Reading

Use this related reading to extend student comprehension after completing the lesson.

  • Student Reading

    for chapter 3

Related Multimedia

  • Density of Water | Chapter 3: Density (7) Density of Water
  • Density of Water | Chapter 3: Density (8) Liquid Water

Other Activities From This Chapter

  • What is Density?
  • Finding Volume—The Water Displacement Method
  • Density—Sink and Float for Solids
  • Density—Sink and Float for Liquids
  • Temperature and Density
(Video) GCSE Physics - Density #26

Teaching Resources

  • for chapter 3

FAQs

What is the density of water? ›

What is the density of water PDF? ›

The density of water is 1 gram per cubic centimeter.

What is the density of water class 9? ›

The density of water is 1000 kg/m3.

Why is the density of water 1000 kg m3? ›

Density of water is taken as 1000 kg/${{\text{m}}^3}$. This value of the density of water (i.e., 1000 kg/${{\text{m}}^3}$) signifies that there is 1000 kg mass of the water present in 1 ${{\text{m}}^3}$ volume of the water.

What is density with answer? ›

Density Definition: Density is the measurement of how tightly a material is packed together. It is defined as the mass per unit volume. Density Formula: ρ = m/V, where ρ is the density, m is the mass of the object and V is the volume of the object.

What is density * Your answer? ›

Density is the mass of an object divided by its volume. Density often has units of grams per cubic centimeter (g/cm3). Remember, grams is a mass and cubic centimeters is a volume (the same volume as 1 milliliter).

What is the density of water class 11? ›

The density of water is approximately 1 gram/ cubic centimetre (1 g/cm3).

What is density class 11? ›

Density of an object is a measure of its mass per unit volume. The average or absolute density of an object equals total mass of the object divided by its total volume.

What is density and its types? ›

Usually, the density is of two types, one is absolute density, and the other is relative density. Relative density is also known as specific gravity, which is the ratio of the density of a material to the density of reference material. Usually, the reference material is water.

Why is Waters density 1? ›

It's no coincidence that water has a density of 1.

Density is mass divided by volume (ρ=m/v), and water was used as the basis for establishing the metric unit of mass, which means a cubic centimeter (1cm3) of water weighs one gram (1g). So, 1g/1cm3 = 1 g/cm3, giving water its easy-to-remember density.

What is density in chemistry class 9 chapter1? ›

The density of a substance is its mass per unit volume.

What is the unit of density? ›

The SI unit of density is m3kg. Density = Volume Mass =m3kg.

What is SI unit of density kg m3? ›

The kilogram per cubic metre (symbol: kg·m3, or kg/m3) is the unit of density in the International System of Units (SI), defined by mass in kilograms divided by volume in cubic metres.

Is the density of water 1kg m3? ›

The density is defined as the mass per unit volume ratio. Pure water has a density of 1g/cm 3 or 1000kg/m 3 .

What is density in kg? ›

Density is a derived unit from two other units: mass and volume. Density is by definition, the amount of mass per unit volume.

What is density full form? ›

density, mass of a unit volume of a material substance. The formula for density is d = M/V, where d is density, M is mass, and V is volume. Density is commonly expressed in units of grams per cubic centimetre.

Is density in simple words? ›

Density is a word we use to describe how much space an object or substance takes up (its volume) in relation to the amount of matter in that object or substance (its mass). Another way to put it is that density is the amount of mass per unit of volume. If an object is heavy and compact, it has a high density.

What is the density symbol? ›

ρ = density in g/cm 3. The symbol for density is the Greek letter rho, .

What is density used for? ›

What is Density? The density of an object is one of its most important and easily-measured physical properties. Densities are widely used to identify pure substances and to characterize and estimate the composition of many kinds of mixtures.

Why is density important? ›

Density is an important concept because it allows us to determine what substances will float and what substances will sink when placed in a liquid. Generally, substances float so long as their density is less than the density of the liquid they are placed in.

What is density in a sentence? ›

Word forms: densities

The region has a very high population density. In science, the density of a substance or object is the relation of its mass or weight to its volume. Jupiter's moon Io, whose density is 3.5 grams per cubic centimeter, is all rock.

What is heavy water class 11 chapter? ›

What is Heavy Water? Heavy water is a compound that is made up of oxygen and deuterium, a heavier isotope of hydrogen which is denoted by '2H' or 'D'. Heavy water is also called deuterium oxide and is denoted by the chemical formula D2O.

What is density of water in SI unit? ›

Hence, the density of water in SI unit is ³ ³ 1000 k g / m ³ .

What is volume density class 12? ›

Volume charge density: When the charge density is throughout the volume of a body, then the charge per unit volume is called volume charge density and it is represented by ρ. ∴ρ=Vq.

What is density by Topper? ›

Density of a substance is defined as the mass per unit volume. Its SI unit is kgm−3. For example, the density of water at room temperature and atmospheric pressure is 1 kgm−3.

What is density in science PDF? ›

1. Density. The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ (the Greek letter rho).

What is density method? ›

Utilizing the VDM-SIMP approach, a topology optimization problem is formulated with an objective of minimizing the mass subject to a single inequality constraint of a specified maximum displacement value at the point where the external load F is applied.

What is basic density? ›

Basic density is defined as the ratio between the oven-dry mass of a wood sample and its green volume. D = M/V.

What are the 3 types of density? ›

There is arithmetic density, physiological density, and agricultural density.

Is the density of water 1 or 1000? ›

In the case of pure water, the density is 1 gm/cm3 or 1000 kg/m3. Pure water's density varies with temperature and reaches its highest point at a temperature of 4 °C, or 1000 kg/m3.

What is water's density kg L? ›

Water has a density of 1 kg /L, that is, 1 liter of water has a mass of exactly 1 kg.

Why is water high density? ›

Each water molecule is made up of two hydrogen (H) atoms and one oxygen (O) atom. The bonds between water molecules are called hydrogen bonds. As water cools to 3.98°C, its mass stays the same but volume decreases – the same mass fits into a smaller space so it is more compact.

What is relative density Class 9 short answer? ›

Relative density, or specific gravity, is the ratio of the density of a substance to the density of a given reference material. It is a unitless quantity.

What do you mean by density write its unit class 9? ›

Density is defined as mass per unit volume. Hence its SI unit is: kg/m3.

Is density a basic unit? ›

Density is an SI derived unit. It is derived from the SI fundamental unit for mass, the kilogram, and the SI fundamental unit for length, the meter. Density is the mass per unit of volume. The SI derived unit for volume is cubic meters.

How do you find the density? ›

The density of an object is the object's mass divided by its volume. The density is characteristic of the material that the object is made of, and its value can help to identify the material.

Who discovered density? ›

Who discovered density? Density was discovered by a Greek mathematician and engineer named Archimedes. He was born in the city of Syracuse, which was the heart of art, commerce and science, and his father, Phidias, was a mathematician and an astronomer.

Why is density kg m3? ›

The units for density

The kilogram (kg) is the standard unit for mass. The cubic metre (m 3) is the standard unit for volume. However, in many laboratory situations mass will be measured in grams (g) and volume in cubic centimetres (cm 3).

How many kg is 1 cubic? ›

Standard cubic conversion is 1 cubic meter of space = 333 kgs. Cubic weight formula.

What is the weight of 1 m3 of water? ›

A cubic metre of pure water at the temperature of maximum density (3.98 °C) and standard atmospheric pressure (101.325 kPa) has a mass of 1000 kg, or one tonne. At 0 °C, the freezing point of water, a cubic metre of water has slightly less mass, 999.972 kilograms.

What is density 7th grade? ›

It is a measure of how tightly packed and how heavy the molecules are in an object. Density is the amount of matter within a certain volume.

What is density and size? ›

Population size and density are the two most important statistics scientists use to describe and understand populations. A population's size refers to the number of individuals (N) it comprises. Its density is the number of individuals within a given area or volume.

What is density 6th grade? ›

The density of a substance is the relationship between the mass of the substance and how much space it takes up (volume). • The mass of atoms, their size, and how they are. arranged determine the density of a substance. • Density equals the mass of the substance. divided by its volume; D = m/v.

Is the density of water 1000 or 997? ›

Water has a density of 997 kg/m 3 at 25 degrees Celsius. The density is defined as the mass per unit volume ratio. Pure water has a density of 1g/cm 3 or 1000kg/m 3 .

Why is the density of water 1 g mL? ›

It's no coincidence that water has a density of 1.

Density is mass divided by volume (ρ=m/v), and water was used as the basis for establishing the metric unit of mass, which means a cubic centimeter (1cm3) of water weighs one gram (1g). So, 1g/1cm3 = 1 g/cm3, giving water its easy-to-remember density.

Is density of water always 1000? ›

The density of water is taken as 1.00 g / cm³ at 4.0°C. It does not matter if you have 1 cm³ , 1 dm³ , 1 kg , or 10,000 kg . The density is always 1.00 g / cm³ at 4.0°C.

Why is water density 1? ›

In practical terms, density is the weight of a substance for a specific volume. The density of water is roughly 1 gram per milliliter but, this changes with temperature or if there are substances dissolved in it. Ice is less dense than liquid water which is why your ice cubes float in your glass.

What is the value of 1 density? ›

The formula for density is d = M/V, where d is density, M is mass, and V is volume. Density is commonly expressed in units of grams per cubic centimetre. For example, the density of water is 1 gram per cubic centimetre, and Earth's density is 5.51 grams per cubic centimetre.

Why is the 1 density of water at 4 C? ›

At 4 °C, the clusters start forming. The molecules are still slowing down and coming closer together, but the formation of clusters makes the molecules be further apart. Cluster formation is the bigger effect, so the density starts to decrease. Thus, the density of water is a maximum at 4 °C.

Is the density of water 1 kg L? ›

Water has a density of 1 kg /L, that is, 1 liter of water has a mass of exactly 1 kg.

What is the density of 100% pure water? ›

1.000 g/mL at 3.98 °C (lit.)

Does 1 mL of water weigh 1g? ›

Remember that 1mL of water weighs 1g. In other words, the density of water is 1g/mL.

What is density in mL? ›

Numerically, this can be expressed as the mass per unit volume and is calculated using the formula: While any units of mass and volume can be used to calculate density the most common are grams (g) and milliliters (ml). This gives density the units of grams per milliliter (g/ml).

What is the density of 1.0g mL? ›

Water has a density of 1.0 g/mL. That density is the same whether you have a small glass of water or a swimming pool full of water.

Is density less than 1? ›

If a substance's relative density is less than 1 then it is less dense than the reference; if greater than 1 then it is denser than the reference. If the relative density is exactly 1 then the densities are equal; that is, equal volumes of the two substances have the same mass.

What is density measured in? ›

Density has the units of mass divided by volume such as grams per centimeters cube (g/cm3) or kilograms per liter (kg/l).

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