In the previous investigation, students discovered evidence the 1cc the water weighs 1 gram.

How would certainly we measure up the load of a single drop that water? as soon as we placed a fall of water on ours classroom scale, it doesn"t register any type of weight at all.

In this conference students use a tiny dropper and a basic understanding of fountain to number out the weight of a single drop that water. Why is this important? This starts a sequence of investigate in i beg your pardon students prolong their understanding of what it means for things to have weight. They progression from endure with objects that have clearly perceptible load to objects for which load is barely perceptible, such as a solitary drop the water. Eventually they think about particles too little to see, whose load becomes obvious only as soon as billions the them room present.

By the end of this investigation college student will understand that once a sample of product is too little to sweet on their scales, they have the right to use their understanding of unit weight and volume to calculation the weight. They will additionally deepen their expertise that even the tiniest objects, such together a single grain that sand, have weight.

Learning Goals

understand that very small things have actually weight sequence of experience
1. Ask the question All Class5 Mins
2. Build a strategy All Class 10 Mins
3. ExploreIndividual 15 Mins
4. Re-superstructure the results All Class5 Mins
5. Do meaning All Class 10 Mins

NGSS Alignment

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Three Dimensional learning
Disciplinary main point Ideas 5-PS1-1, 5-PS1-2

Materials have actually weight and also take up an are and are matter.

You are watching: How much does a drop of water weigh

Very little pieces (particles) of matter have weight and also take up space.

Practices Engaging in debate from evidence: : In the critical investigation, student learned the 1cc the water weighs 1g. They counting the number of drops the water exit from a 1cc syringe and, making use of mathematics, they make claims around the weight of a solitary water drop. Constructing explanations: : offered that a single water fall or grain of sand has no perceptible weight, students explain why a bucket the water or pail the sand have the right to have far-reaching weight.
Crosscutting Concepts Scale, proportion and quantity: students use their expertise of the weight:volume ratio of water to create the load of a solitary drop of water.

Materials and Preparation

For the class:


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article the examination question in a place where all students can see it. Do a class table titled, "What go a drop of water weigh?"; an example is uncovered in action 4. 1 digital range

For each group:

2 12oz cups approximately 1/2 complete of water 4 1cc droppers (1cc little syringe) 4 centimeter cubes 4 paper towels
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We know just how to weigh the quantity of water in our mini-lakes, yet how could we weigh the water in a raindrop? introduce today"s examination question:

What walk a drop of water weigh?

Give college student a possibility to share ideas. Difficulty students to aid refine the investigation question:

space all autumn the exact same size? What dimension drop of water do we weigh? deserve to we control the size of a drop? have the right to we rely on the classroom range to carry out the answer?

Acknowledge that drops deserve to be various sizes, and also explain that the course has a tool-a dropper-that makes a uniform fall of a details size.

Show student the dropper, a 1cc syringe. The course will resolve today"s examination question by identify the weight of one drop from this dropper.

Revise the investigation question come read:

What does a drop of water from our classroom dropper weigh?

Post the rephrased examination question.


Strategy 1: use the scale.

It"s most likely someone will suggest putting one or more drops top top a scale. Explain that if us had much more accurate scales, this strategy can work.

Demonstrate put a single drop of water top top the scale. The range will not register any type of weight. Also when put multiple fall of water top top the scale, one drop in ~ a time, it"s unlikely this scales will register weight. If lock did, the weight would certainly be rounded come the nearest gram, offering inaccurate results.

Encourage students to come increase with one more strategy.

Strategy 2: use the details that 1 cubic centimeter of water weighs 1 gram.

over there is a means to usage something we discovered in the last investigation-that one cubic centimeter that water weighs one gram-to aid us prize the investigation question. How can counting the drops in 1cc the water aid us? If we might make simply 2 drops of water native one totality cubic centimeter the water, what would each of those fall weigh? If we can make 10 fall of water from one totality cubic centimeter that water, what would certainly each of those autumn weigh?

Fill and also weigh a dropper

Place one empty dropper top top a class scale and read the weight (approximately 3g).


Point out that the dropper has actually marks on it that allow us to include exactly one cubic centimeter that water. Demonstrate a conventional procedure because that accurately filling the dropper with 1cc of water:


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push the plunger as far as that will enter the barrel the the dropper. Put the pointer of the dropper in a cup the water and slowly traction on the plunger to completely fill the dropper. Point the pointer of the dropper towards the ceiling and tap the barrel through a finger till all wait bubbles have risen out of the water. Very closely depress the plunger till the black ring that the seal aligns with the 1cc mark.

Place the dropper ~ above the scale again. It must weigh one gram more than the weight as soon as empty.

Demonstrate make drops


To prize the question, What does a fall of water from ours classroom dropper weigh?, it"s necessary that everyone use the very same tool in the same means in order to obtain accurate results. Demonstrate a conventional procedure to do drops:

organize the dropper vertically, tip down, around 1 inch over a workdesk top. Gently push the plunger to release one fall of water. Relocate the dropper sideways around 2 inches and also release another drop. Kind a line of 5 or 6 drops.

Keeping the drops separate from one one more makes it possible to counting them after the dropper is empty, in the event someone loses counting while making the drops.


Distribute the materials. Students use the file towel for drying desktops after ~ counting the drops. The function of the centimeter cube is to present the volume of the 1cc dropper in another shape - come reinforce the size of 1cc the water. Each cubic centimeter takes increase the same amount that space, together the one cubic centimeter the water student will add to their droppers.

Emphasize the importance of everyone using traditional procedure because that both filling and emptying the droppers. Ask students to exercise once prior to they usage the droppers to get a last count.

Students have to make a long row of autumn on your desktops as they slowly empty the dropper, keeping the tip around 1 inch above the desktop.


Note: because the droppers can come to be a distraction, collect them as shortly as students have actually completed their actual count.


Survey the class for the results and enter their data in a course chart, questioning each student to determine the weight of one drop when they carry out the variety of drops made.

What go a drop of water weigh? load of water number of drops load of 1 drop 1g 1g 1g etc.
29 1/29thg
30 1/30thg
32 1/32ndg

Address the examination question:

What go a fall of water from our classroom dropper weigh? walk a fall of water weigh more or less than one gram?

about 1/30th that a gram?

Have students complete the science Notebook web page .


Note: here is one more example of tiny differences in a instance where one can expect everyone to get the same result. Student should know the possible reasons because that the differences and also agree to pick a "typical" worth for the load of one drop.


Acknowledge that students have just finished some amazing work; castle used mathematics to figure out the load of miscellaneous that had too tiny matter for the classroom scale to sense.

See more: 32 Mm Equals How Many Inches Conversion (Millimeters To Inches)

Purpose of the discussion

The function of this discussion is for students come jointly construct explanations for exactly how objects such as a bucket that water or sand have the right to have far-reaching weight, provided that a solitary drop that water or grain of sand has no perceptible weight.

Engage college student in the emphasis question

If a drop of water weighs just 1/30th the a gram, just how do you explain why a bucket the water is for this reason heavy?

There space many, plenty of drops of water in a bucket full of water.Each fall contributes something to the total weight the the bucket that water.

Allow time because that students to formulate responses. Encourage full participation by questioning for others to share their own explanations and also to respond to the explanations the others.

Do friend think a single grain the sand weighs anything? explain your answer.

If students insurance claim "yes", what reasoning deserve to they carry out to support their claim? If students insurance claim "no", ask for the explanation; that will aid you determine whether students are focusing on even if it is a grain of sand will register any kind of weight top top the scale, or if students think a grain of sand has actually no weight.

How go a bucket of sand obtain to be so heavy when a grain of sand weighs so little?

there are plenty of millions of seed of sand in a bucket, with each serial contributing a tiny little of load to the full weight that the bucket that sand.

Can girlfriend think that other examples of small bits the seem to have actually no weight individually, but that have the right to be merged together to have far-reaching weight?

seed of street or salt; particles of flour.

Summarize the discussion and also recap the investigation

Using the exact same language students have actually used, summarize their main ideas. Include the following crucial ideas:

If a large collection of seed of sand (or fall of water, etc.) have actually weight, climate we deserve to reason the each separation, personal, instance grain must have actually some weight, also if that weight is too tiny to sense or measure. Back individual grains of sand or drops of water may have actually imperceptible weight, combine millions or billions the them with each other can result in far-reaching weight.

Recap the following:

tiny things, such as drops of water, room not heavy sufficient to register weight on the great scales.We"ve determined how to calculate the load of a water drop and concluded that tiny things such as solitary drops the water or seed of sand actually have weight.

When we think around how hefty a bucket that water feels, or a bucket the sand feels, it have the right to make united state wonder, "How numerous of those drops, or grains, room there in a bucket, to make it feeling so heavy?"