Name:
Date:
What’s in an Atom?
Objective: To build atoms to better understand the basic building blocks of life and their
components.
Warm up:
1) What charge do electrons have? Protons? Neutrons?
2) Where are the electrons, protons and neutrons found in an atom?
Materials:
1) Three colors of Play Dough
2) Sticks
3) Scissors
Today we will be building atoms to learn what makes them. First you will design your own atom
without looking at the periodic table following these guidelines.
1) The first “electron shell” of the atom should only contain two electrons. The next shells will
contain up to eight electrons.
2) Place the protons and the neutrons together in the nucleus (or center) of the atom.
How many elections did you have? Protons? Neutrons?
Lets look at the periodic table together. What atom did you create?
Atoms are the building blocks of the vivid world around us. They are the focus of the
study of chemistry, and biology is the study of how chemistry makes life work. Atoms are the
basic building blocks of compounds, and the periodic table contains all of the atoms known or
created so far. Atoms are made up protons, neutrons, and electrons. The number of protons in
the nucleus of the atom determines what element it is. Atoms are organized on the periodic table
by the atomic number. The neutrons are also found in the nucleus and tell what isotope the
element is.
To figure out how many neutrons an element has you subtract the atomic number from
the atomic mass.
The electrons are found in an electron cloud surrounding the nucleus of the atom. They
are what give the atom its chemical properties such as attraction and reactivity to other atoms.
When we talk about the atoms on the periodic table they have a neutral charge, so the amount of
electrons is equal to the amount of protons. This changes when the atoms in the world around
you start to interact with each other.
Atoms can exist in a few forms and these are called isotopes. You may have made an
isotope in our first activity. These are atoms with the same number of protons, but different
numbers of neutrons.
Atoms are important in biology. When elements and compounds interact with our bodies
there are varying affects. Sometimes a disease in our bodies is caused by a simple addition or
deletion of atoms; an example of this is sickle cell anemia. In sickle cell anemia your blood cells
are not the right shape and are not able to correctly carry oxygen around your body. If your body
cannot get the oxygen it needs you will not survive!
In addition, the drugs that we are administered when we are sick are also typically small
compounds made of a few to about a hundred atoms. Every process that our bodies perform
involves chemistry and underlying that are chemical reactions involving atoms.
We will be building models of atoms to better understand what they are and what they
look like. Models are used in science to visualize things that may either be too small or too large
to see. We can use models to explore and manipulate things to better understand them. We can
also use models as references when we are studying and doing research.
Define:
Atomic number-
Atomic mass -
Isotope-
Electron shell-
3) How many electrons does a hydrogen (H) atom have? A helium (He) atom? What about
protons and neutrons?
4) Bonus question: What is larger? A proton or an electron?
Directions:
A periodic table is attached to this work sheet. Look at the periodic table and choose an atom to
build with your partner. Pick an atom that lies in rows 1-3 on the periodic table. Do not pick
hydrogen; this was already made for you.
Next, decide how you will build your atom. Draw your atom below before you make your model.
Questions
5) What is the symbol (or name) of your atom? How many protons, neutrons, and electrons does
it have? What charge does it have?
6) Using a computer, look up what the symbol of your atom is. What is this element used for?
Where is it found in our world?
7) What if you took one electron away from your atom, what charge would it have? How could
you turn it into the next atom on the periodic table?
8) Why are atoms important in biology? Write 3 reasons why atoms are important (examples
may include atoms that cause disease, atoms that we need to survive)
Extension: 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.