Guess That Item: Atomic Structure

Learning Resource Type

Learning Activity

Subject Area

Science

Grade(s)

8

Overview

This activity can be used as an introduction to atomic structure. Students will be given several sealed envelopes and asked to use their senses to identify the objects inside. Students aren't allowed to open the envelopes, but they may use any of their senses to figure out what is inside. The teacher can compare this activity with the discovery of the atom and its structure.

This activity is a result of the ALEX Resource Development Summit.

Phase

Before/Engage
Science (2015) Grade(s): 8

SC15.8.1

Analyze patterns within the periodic table to construct models (e.g., molecular-level models, including drawings; computer representations) that illustrate the structure, composition, and characteristics of atoms and molecules.

UP:SC15.8.1

Vocabulary

  • Element
  • Atom
  • Protons
  • Nucleus
  • Electrons
  • Neutrons
  • Atomic number
  • Periodic table
  • Array
  • Atomic mass
  • Period
  • Group
  • Chemical properties
  • Physical properties
  • Molecule
  • Bond
  • Chemical bond
  • Valence electron
  • Ion
  • Ionic bond
  • Nonmetal
  • Metal
  • Covalent bond
  • Metallic bond
  • Conductivity

Knowledge

Students know:
  • Elements are substances composed of only one type of atom each having an identical number of protons in each nucleus.
  • Atoms are the basic units of matter and the defining structure of elements.
  • Atoms are made up of three particles: protons, neutrons and electrons.
  • The number of protons in an atom's nucleus is equal to the atomic number.
  • The periodic table arranges all the known elements in an informative array.
  • Elements are arranged left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass.
  • Rows in the periodic table are called periods. As one moves from left to right in a given period, the chemical properties of the elements slowly change.
  • Columns in the periodic table are called groups. Elements in a given group in the periodic table share many similar chemical and physical properties.
  • The period number of an element signifies the highest energy level an electron in that element occupies (in the unexcited state). The number of electrons in a period increases as one traverses down the periodic table; therefore, as the energy level of the atom increases, the number of energy sub-levels per energy level increases.
  • A molecule is formed when two or more atoms bond together chemically.
  • A chemical bond is the result of different behaviors of the outermost or valence electrons of atoms.
  • Ionic bonds are the result of an attraction between ions that have opposite charges. Ionic bonds usually form between metals and nonmetals; elements that participate in ionic bonds are often from opposite ends of the periodic table. One example of a molecule that contains an ionic bond is table salt, NaCl.
  • Covalent bonds form when electrons are shared between atoms rather than transferred from one atom to another. The two bonds in a molecule of carbon dioxide, CO2, are covalent bonds.
  • Metallic bonds exist only in metals, such as aluminum, gold, copper, and iron. In metals, each atom is bonded to several other metal atoms, and their electrons are free to move throughout the metal structure. This special situation is responsible for the unique properties of metals, such as their high conductivity.

Skills

Students are able to:
  • Analyze patterns within the periodic table to construct models of atomic and molecular structure, composition, and characteristics.
  • Identify the relevant components of the atomic and molecular models.
  • Describe relationships between components of the atomic and molecular models.

Understanding

Students understand that:
  • Patterns in the periodic table predict characteristic properties of elements. These trends exist because of the similar atomic structure of the elements within their respective group families or periods, and because of the periodic nature of the elements.
  • The structure, composition, and characteristics of atoms and molecules are dependent upon their position in the periodic table.

Scientific and Engineering Practices

Developing and Using Models

Crosscutting Concepts

Patterns

Learning Objectives

Students will describe the basic structure of an atom.

Activity Details

The students will be given several sealed envelopes and the Guess That Item worksheet and will be asked to identify the object inside. The students will be allowed to use any of their senses to identify the object as long as they don't damage or open the envelope. Students will work in groups and the envelopes will rotate around the classroom. Students should be given a period of time to identify the object (4 minutes) and then pass the object on to the next group. The teacher will lead a discussion at the end comparing this activity to how the structure of the atom was discovered. The teacher may choose to open the envelope, or they may allow it to remain a mystery.

Assessment Strategies

Students will students sketch and label an atom. The teacher can check for understanding of the basic structure of the atom. 

Background / Preparation

The teacher must find several objects (bolt, eraser, marble, etc.) to place in envelopes and seal. Eight to ten envelopes are recommended. Larger classes will require more envelopes. Print copies of the worksheet or share with students. Number the envelopes so that the students may answer the worksheet.

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