`
What is an Atom?
Curriculum Guide
Part of: Inquiry
Science with Dartmouth
Britney Tappen
GK-12 2015
Overview
Everything in the universe around us is made up of atoms. From simple elements to something as
complex as the human body, atoms are involved in all of the processes that allow life to happen here on
earth. In this lesson students will build models to explore the structure of atoms and to gain a better
understanding of their make-up and structure.
Science Standards (NH Science Curriculum Frameworks)
PS – Physical Science
PS1– All living and nonliving things are composed of matter having characteristic properties that
distinguish one substance from another (independent of size/amount of substance)
S:PS1:11:1.1 Recognize and describe the structure of an atom and explain how the major components
interact with one another.
S:PS1:11:1.2 Recognize how elements are arranged in the periodic table; and explain how this
arrangement illustrates the repeating patterns among elements with similar properties, such as the
relationship between atomic number and atomic mass.
S:PS1:12:1.1 Understand the basic building blocks of matter are quarks and leptons.
S:PS1:11:1.3 Explain that neutrons and protons are made up of even smaller constituents.
S:PS1:12:1.3 Identify the sub-orbital shapes and geometric orientations of the orbitals electrons can
occupy in atoms.
S:PS1:11:1.4 Define isotopes; recognize that most elements have two or more isotopes; and explain that
although the number of neutrons has little affect on how the atom interacts with others, they do affect the
mass and stability of the nucleus.
S:PS1:11:1.6 Model and explain the structure of an atom or explain how an atom’s electron configuration,
particularly the outermost electron(s), determines how that atom can interact with other atoms. [PS1(911)MAS+FAF-4]
S:PS1:11:2.2 Determine whether an atom is either electrically neutral or an ion by referring to its number
of electrons.
Focus Question
What makes up an atom and how do all of the components come together to make the complex world
around us?
Objectives
Through this lesson, students will:
- Design models of atoms and discover what they have created
- Learn about the different components that make up atoms.
- Understand what atoms are stable in nature
- Obtain a basic level of understanding about the periodic table
- Relate the importance of atoms to biology
Vocabulary you may need to do the activity
Nucleus: The center of an atom.
Protons: Positively charged particles in an atom, they are found in the nucleus, they define what element
an atom is. (Example: If you look at a periodic table, 1 is always Hydrogen, 2 is always Helium, this
corresponds to the atomic number, see below)
Neutrons: Neutral charged particles in an atom, they are found in the nucleus.
Electrons: Negatively charged particles in an atom, they are found outside of the nucleus. (fun fact: they
are much smaller than protons and neutrons)
Atomic number: The number of protons in the atom.
Atomic mass: The number of protons and neutrons in an atom.
Isotope: An atom that has the same number of protons but different number of neutrons. This changes
the atomic mass of an element.
Valence Electrons: The outermost electrons in an atom.
Rows of the periodic table: Reading the periodic table from left to right horizontally. H and He are in
the first row, Li-Ne is the second row.
Columns of the periodic table: Reading the periodic table from top to bottom. There are 8 columns we
will focus on in this lab. The first three rows contain 8 columns. The column numbers 1-0 (0
corresponding to column 8) correspond to the valence electrons in the atoms. (see picture below)
Compounds: More than one atom bound together. Compounds typically involve two atoms sharing
electrons.
Background
In biology we learn about the processes that occur in nature that allow the world around us to function.
Chemistry explains these life processes. The purpose of this lab is to introduce the most basic unit of
chemistry, the atom, so that students have a better understanding of the processes that they will study in
biology. This also introduces the idea of creating models to study things that are either too small or too
large.
Materials (For 20 students working alone)
-Three colors of Play-dough (or clay) (10 containers)
-Wooden skewers (different lengths or ones that can be cut) (100)
-Periodic table of the elements
-Scissors
-Atom lab worksheet
Preparation
Gather all materials required for the lab including print outs of the periodic table for each student.
Review electrons, protons, and neutrons and where they reside in an atom with the class.
Procedure
1) Background: Talk about why atoms are important in biology. All biological processes are
chemical reactions. One example includes how enzymes function – each enzyme in our bodies
has a specific set of atoms that it requires to perform it’s function, without those atoms it will not
function correctly. An example of a disease caused by a change in atoms is sickle cell anemia,
the difference (in DNA the base A to the base T, just a few atoms makes a huge difference!)
causes a decrease in the cells ability to carry oxygen through the blood because it changes the
shape of red blood cells!
faculty.ccbcmd.edu
2) Research: Review electrons, protons, and neutrons and where they are found in an atom. Make
sure to include the rules of electrons. Only 2 electrons can be in the first electron shell of an
atom, and then 8 electrons can be in the subsequent shells. Talk about why models are important.
Have the students brainstorm why we need models in science, sometimes things are too large to
understand (solar system models), and sometimes too small (atomic models).
3) Demonstrate: Make a model of the hydrogen atom. This model should have one colored piece of
play-dough in the center, a stick, and another piece attached to the stick of a different color. This
will prompt them to begin creating their own atoms.
Examples:
Hydrogen (Green- 1 proton, Black- 1 electron)
Helium (Green- 2 protons, Yellow- 2 protons, Orange- 2 electrons)
4) Activity: Given the rules “only 2 electrons can be in the first electron shell of an atom, then 8
electrons can be in the subsequent shells” and the materials required, allow students to make their
own atomic models without looking at the periodic table.
5) Discuss and share: Once the class has made their creations, discuss what they have made. Talk
about the periodic table and how to read it. Looking at the figure below, have the students try and
figure out what element they made in partners or small groups. Students can share their elements
with the whole class. They can also put there name on the periodic table next to the element they
made.
How do we calculate the number of neutrons? (Atomic mass- atomic number = neutrons)
If it is not found on the periodic table is it an isotope of an element that is found there? Have the
students discuss what they have done to build their models.
6) Lesson: Now that they have explored designing models, review in more depth how the atoms on
the periodic table get their location. Talk about valence electrons, or the number of electrons
found in the outermost level of the atom and how in the first three rows, the column that the atom
is on the periodic table corresponds to the number of electrons in it’s outer most shell or electron
shell. Fill in the vocabulary on the worksheet together. (Examples: Na is in the first column so it
has 1 valence electron, C is in the 4th column so it has 4 valence electrons). For the sake of this
exercise do not go past the first three rows. Also talk about isotopes.
7) Activity: Instruct the students to create a model of an atoms found in the first three rows of the
periodic table. If the resources are available, have the student look up what the atom is and what
it is used for/found in.
8) Relate the lab back to biology: Have the students do some exploration into why atoms are
important in biology and write 1-3 reasons as homework (or in class if there is time)
Assessment
1) Have the students build models of atoms found on the periodic table to demonstrate their
understanding of it (Number 7 above)
2) Have the students do some exploration into why atoms are important in biology and write 1-3
reasons as homework (or in class if there is time)
Extensions
1) Extend the experiment: If your class is doing well you can ask them to pair up and make
compounds from their atoms. The rules for this is that each atom still only wants no more than 8
electrons in its outermost shell, so atoms need to share electrons. Once the students have
explored this with their partners have them research whether or not that compound exists in
nature.
Example (2 Hydrogen Atoms or H2)
Two hydrogen atoms join together to make H2. (Green- protons, Black- Electrons) So 1
Hydrogen atom (1 set of green and black) binds to another to form the H2 compound.