Classroom activity Grade 1 Science

Drops on the Cold Jar at Pipersfield School

A grade 1 activity in which teams check three sealed jars at the hour and half hour, write each time, and find out why only the ice-water jar turns wet outside.

Grade: Grade 1
Subject: Science
Material: Classroom activity
Time: 60 min
Prep: Low prep
Materials: 3 clear jars with tight lids, Ice cubes, Blue food coloring, Dry white paper towels, A tray, A wall clock the class can read

Standards

1.MD.B.3 Common Core Math

Tell and write time in hours and half-hours using analog and digital clocks.

How this material aligns: The class reads the wall clock at three checks spaced a half hour apart, and handout items 1 through 3 have each student write those hour and half-hour times on the record page.

All materials for 1.MD.B.3 →

W.1.2 Common Core ELA

Write informative/explanatory texts in which they name a topic, supply some facts about the topic, and provide some sense of closure.

How this material aligns: The closing item has each student name the cold jar as the topic, supply two facts they observed about it, and finish with one closing sentence.

All materials for W.1.2 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-09-03.

Objectives

Students will read the classroom clock and write the time of each jar check.
Students will compare which of three sealed jars turns wet on the outside.
Students will write about the cold jar, giving two facts from their own checks and a closing sentence.

Vocabulary

Key words: drops, wet, dry, sealed, air

Teacher overview

Three sealed jars sit on a tray by the window in Room 2 at Pipersfield School for one hour, and teams visit them three times, one half hour apart, to check whether each jar is wet or dry on the outside. Only the jar holding ice water turns wet, and because the water inside that jar is tinted blue while the drops on the outside are clear, the class can rule out the explanation students most often give, which is that the water leaked out through the glass or through the lid. The activity works with the whole class in teams of three or four, and it needs only about ten minutes at each check, so ordinary lessons continue in between.

Activity Directions

Before students arrive, fill Jar 2 with room-temperature water and stir in two drops of blue food coloring, and leave Jar 3 empty. Fill Jar 1 last, just before you gather the class, with ice and water and the same two drops of blue coloring. Screw all three lids on tightly and set the three jars on a tray where the whole class can reach them.
Gather the class at the tray. Point out that every lid is closed tight, then wipe the outside of each jar dry in front of the class and point out that each jar is dry right now. Ask students to predict which jars will be wet on the outside later, and record the show of hands on the board.
Sort students into teams of three or four and give each team a record page. Assign each team a first jar to check, so the teams are spread across the three jars.
Check 1, started on the hour or the half hour: read the wall clock together as a class and have every student write that time on the record page. Each team then touches a dry paper towel to the side of its jar, leaving the jar on the tray, decides whether the jar is wet or dry, and circles the answer.
Send teams back to their seats and continue with your regular lesson.
Check 2, one half hour later: read the clock together again and have students write the new time. Teams rotate one jar to the right so that each team now checks a different jar, touches the paper towel to it, and circles wet or dry.
Check 3, one half hour after that: read and write the time once more. Teams rotate again, so by now every team has checked all three jars.
Gather the class at the tray for the last five minutes. Hold up the ice-water jar and ask a student to press a clean white paper towel against it, then show the class that the wet mark on the towel is clear, not blue.
The activity ends once the class has agreed on which jar was wet and where those clear drops came from, which is the air around the cold jar rather than the water sealed inside it.
Debrief with two questions: "The lid was tight the whole time, so how do we know the drops did not come from inside the jar?" and "Both jars held water, so why did only the cold one get wet on the outside?"

Drops on the Cold Jar at Pipersfield School — Grade 1 Science

Name: ____________________________ Date: ______________

Student Handout

Write on this page at each check.

Check 1 time: _____ Jar: _____ Circle one: wet or dry

Check 2 time: _____ Jar: _____ Circle one: wet or dry

Check 3 time: _____ Jar: _____ Circle one: wet or dry

Write the time of Check 1.
Write the time of Check 2.
Write the time of Check 3.
Which jar was wet on the outside: the ice-water jar, the warm-water jar, or the empty jar?
The water in the ice-water jar is blue. What color were the drops on the outside of it?
The lid was closed tight the whole time. So where did the drops on the outside come from?
Write about the cold jar. Tell what you saw at the first check. Tell what you saw at the last check. Then write one more sentence to finish.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key

Answer: Answers will vary.
Accept the clock time the class read together at the first check, written to the hour or half hour.
Answer: Answers will vary.
Accept the time one half hour after Check 1, written to the hour or half hour.
Answer: Answers will vary.
Accept the time one half hour after Check 2, written to the hour or half hour.
Answer: The ice-water jar.
The other two jars stay dry. The warm-water jar has the same water and lid, so a leak would wet it too, and the empty jar shows a jar by itself stays dry, so the cold is what makes the drops.
Answer: Clear.
The drops on the outside carry no blue coloring, so they cannot be the tinted water sealed inside the jar.
Answer: From the air.
Water is in the air around us, and when that air touches the cold glass the water in it turns into drops on the outside of the jar.
Answer: Answers will vary.
Look for the jar named as the topic, two facts drawn from the checks, such as the jar being dry at the start and wet later, or a few drops at the first check and more at the last, and a closing sentence.

Differentiation

Support

Give students a record page with the three clock faces already drawn and the hands missing, so they only draw the hands rather than writing the digits, and pair each of these students with a partner who reads the wall clock aloud.

Extension

Ask a team to set up a fourth jar with ice water and no lid at all, predict whether it will behave like Jar 1, and explain to the class afterward why the missing lid does not change the result on the outside of the glass.

ELL supports

Pre-teach "wet," "dry," "drops," and "sealed" by touching the jars while saying each word, and post a two-word answer frame, "wet" and "dry," beside the tray. Allow item 7 to be dictated to an adult or drawn with labels instead of written in sentences.

Extensions

On a cold morning, ask students to look at the classroom windows and report whether they see drops, then hold a short discussion about which side of the glass those drops are on and what that tells them about where the water came from.