Hands-on Activity Gumdrop Atoms

Learning Objectives

After this activity, students should be able to:

• List the basic components and structure of the atom.
• Identify the electrical charge of an atom and its subatomic particles.
• Explain how engineers use their knowledge of atoms to create new technologies.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

Common Core State Standards - Math

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each group needs:

• 4 red gumdrops
• 3 green gumdrops
• 3 blue/purple/white gumdrops
• 4-5 wooden toothpicks
• 3 long wooden skewers
• 10 small sticker dots
• Atom Worksheet

Note: Non-sugarcoated gumdrops work better for this activity. If sugarcoated gumdrops are used, students will need to use staples to attach the dot stickers to the gumdrops.

Worksheets and Attachments

Pre-Req Knowledge

Students should have some knowledge of atoms as the basic building blocks of matter.

Introduction/Motivation

Have you ever wondered what everything around you is made of? Are things made up of tiny particles that we cannot see? Yes, they are. These tiny building blocks of matter are called atoms and they make up everything we see around us, even ourselves. In this activity, we are going to learn about the atom. We will learn about the parts of an atom, its structure, and learn how to determine the charge of an atom. We will also learn how atoms come together to form molecules!

Molecules can be broken down into atoms, but can the atom actually be broken down into smaller parts? Yes, it can. Several subatomic particles make up an atom. The three main ones are protons and neutrons, which are found in the nucleus or core of the atom, and electrons, which are found floating around in shells outside of the nucleus. Physicists have recently divided atoms into even smaller subatomic particles such as fermions (quarks, leptons, neutrinos, electrons) and bosons (gluons, photons, gravitrons). It is difficult (if not impossible) to determine the physical properties of something based on the number or quarks and leptons it contains. The things we see in our world (water, wood, metal, skin, teeth) are better understood and organized by using the number of protons, neutrons and electrons their atoms (and molecules) contain. Just as we look at the shapes of different LEGO™ pieces, rather than the plastic that makes them, today we are just going to look at protons, neutrons and electrons as the "LEGOs" of matter.

Did you know that atoms have energy? Well, these tiny subatomic particles are constantly moving or vibrating and we cannot even tell. For example, if you look at a molecule of water, it is made up of two hydrogen atoms and one oxygen atom. The electrons in each of these atoms that make up the water molecule are moving all around in their electron shells, or clouds. The outermost electrons in an atom are sometimes shared with another atom. That is how the molecule is formed. The large oxygen atom in a water molecule shares electrons with the hydrogen atoms.

How is this sharing possible? Well, it depends on the electrical charge of the atom. Each of our three subatomic particles in the atom has a type of charge. Protons have a positive charge or +1 charge on them. Electrons have a negative charge or a –1 charge to them. Neutrons are neutral or have no charge. When the overall charge of an atom is neutral, then there are an equal number of protons and electrons. If there are more protons than electrons, though, the atom is positively charged. If there are more electrons than protons, the atom is negatively charged. Any atom with a positive or negative overall charge is called an ion.

Do you think we can apply our knowledge of atoms and their structure to engineering? Yes! For example, how do engineers know that steel is extremely strong? Engineers know this because they know the characteristics of the atoms that make up steel. They know how the parts of each atom interact with each other to create a compound that has specific properties. Engineers and scientists have even been able to develop new atoms and elements that have specific properties that they need to create certain materials and technologies. Engineers use atoms, knowledge of their structure and how they bond, to make new medicines and products to help people. For example, environmental engineers need to know the properties of water molecules and the atoms that make up water molecules to design clean water and air treatment technologies to fight pollution.

Procedure

Background

The goal of this activity is for students to understand the basic structure of an atom. This consists of the location and charge of protons, neutrons and electrons.Additionally, students will understand that molecules are made up of atoms in the same way that atoms are made up of protons, electrons and neutrons.

Students should be made aware of inaccuracies of the gumdrop model. Namely, the model does not correctly display the distances between the nucleus and electrons. Atoms are mostly empty space. For example, if the nucleus of a hydrogen atom were three miles wide and located in Kansas, its electrons would orbit near the East and West Coasts.

Before the Activity

• Gather all necessary materials.
• Make copies of the Atom Worksheet.

With the Students

1. Divide the class into pairs and distribute one copy of the Atom Worksheet to each pair.
2. Distribute gumdrops (4 red, 3 green, 3 blue/purple/white), toothpicks, skewers and sticker dots to each group.
3. Instruct students to draw a "+" on three sticker dots, a "0" on four sticker dots, and a "-" on three sticker dots.
4. Have students stick the "+"sticker dots to the 3 green gumdrops for protons, the "0" sticker dots on the 4 red gumdrops for neutrons, and the "-" sticker dots on the 3 blue/purple/white gumdrops to represent electrons. Explain that "+" means positive charge, "0" means no charge, and "-" means negative charge.
5. Next, have students combine protons and neutrons in one cluster (using toothpicks broken in half) to form the nucleus. Ask what charge the nucleus has by itself and discuss why. (Answer: Positive; the nucleus is positive because it contains positive protons and neutral neutrons.)
6. Then, have students place each electron on one end of a skewer, and stick the other end of the skewer in the nucleus to make a complete atom. Ask what charge the whole atom has and discuss why. (Answer: The atom has no charge because a negatively-charged electron balances out each positively-charged proton in the atom.)
7. Instruct students to remove one electron from the atom. What is the charge of the atom now? (Answer: Positive. If an atom loses an electron (-), it becomes positively charged; because there are now more positive protons than negative electrons. If an atom picks up an electron (-), it becomes negatively charged; because there are now more negative electrons than positive protons. Electrically neutral atoms always have an equal number of electrons and protons, because the charges cancel each other out.)
8. Now have the students get together with other students to join their own atoms to make molecules. If the elements are available, have the students move around the room and get together with other students to make known, simple molecules, such as water.

Note: Activity adapted from the Miami Museum of Science: http://www.miamisci.org/ph/lpexplain2.html

Assessment

Pre-Activity Assessment

Atom Detectives: Solicit, integrate and summarize student responses to the following questions.

• Can anyone name a specific type of atom? Can you find those types of atoms in the classroom? Have students name a few different atoms and where they might be found. For example, water contains oxygen and hydrogen.

Activity Embedded Assessment

Worksheet: Have students complete the Atom Worksheet. Review their answers to gauge their mastery of the subject.

Post-Activity Assessment

What's the Charge? Engineers might need to know the electrical charge of an atom when designing new technologies. Have students determine the overall charge of the following atoms. Remind students that if there are more protons than electrons, then the atom is positively charged. If there are more electrons than protons, the atom is negatively charged. (Note: these ions may or may not occur naturally.)

• The atom has 6 protons, 8 neutrons and 6 electrons. (Answer: The charge is neutral. The atom is carbon-14.)
• The atom has 11 protons, 11 neutrons and 10 electrons. (Answer: The charge is positive. (+1) The atom is sodium.)
• The atom has 8 protons, 8 neutrons and 9 electrons. (Answer: The charge is negative (-1). The atom is oxygen.)
• The atom has 7 protons, 7 neutrons and 5 electrons. (Answer: The charge is positive (+2). The atom is nitrogen.)
• The atom has 29 protons, 29 neutrons and 29 electrons. (Answer: The charge is neutral. The atom is copper.)

Engineering Discussion: Ask a discussion question to get students to think about how engineering incorporates knowledge of atoms and atomic structure. How do engineers use the knowledge of the physical and electrical properties of different atoms? (Answer: Knowing what makes up an atom and how subatomic particles interact allows engineers to build stronger buildings, make more efficient medicine, and improve our daily lives through pollution control and consumer products.)

Safety Issues

Watch that students do not poke their neighbors with the toothpicks or skewers, as the fine filament structure of the wooden toothpicks and skewers can puncture the skin and leave nasty splinters.

Troubleshooting Tips

Remind the students that the gumdrops are for learning, not eating. It often helps to have an extra bag of gumdrops for the students to share and eat after the activity.

The students can use staples or glue to attach the sticker dots if they do not stick to the gumdrops.

Activity Extensions

Human Lithiium Atom: This activity demonstrates the huge amount of space between the nucleus and the electrons and dispels the common misconception that the electrons are located close to the nucleus. Have students make a human model of a lithium atom (same number of protons, neutrons and electrons as the gumdrop activity) on the playground or in the gymnasium. Students can wear T-shirts or caps of the same color, if possible, to represent protons, electrons and neutrons. Students can add pluses, minuses, or zeros, made out of electrical tape, to their shirts. Next, have students act in the roles of the protons, neutrons and electrons, with the "nucleus" (protons and neutrons) as close to the center of the playground as possible and the electrons running around the edge of the playground. This human model is a little closer to scale, but still far different than the relative distances of an actual atom. In reality, if the nucleus formed by the students on the playground is about two feet wide (or a group hug made up of seven kids), then the electrons in the outside shell should actually be a mile away from the nucleus, not just at the edge of the playground!

References

Copyright

Contributors

Supporting Program

Acknowledgements

The contents of this digital library curriculum were developed under a grant from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and National Science Foundation GK-12 grant no 0338326. However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.