The Pluses and Minuses of Protons and Electrons:
All Carbon atoms are alike; they have the same number of protons. In the same way, all
Oxygen atoms are alike, all Iron atoms are alike, and so on. Each kind of atom is an element;
the atoms of each element contain a specific number of protons.
In a neutral atom, the number of protons and electrons are equal. Therefore, the atoms of
different elements differ in the number of protons and electrons they contain.
Electrons are organized within orbitals (in an “electron cloud”) around the nucleus. Atoms
with more electrons, such as Uranium, which has 92 electrons, tend to be larger than
atoms with fewer electrons, such as Hydrogen, which has 1 electron.
Let’s Add in Neutrons (Atomic Mass or Mass Number)
Atoms also differ in mass- the amount of stuff or matter in something. The mass of an
atom is related to its number of protons and neutrons. Mass is measured in atomic mass
units (amu). Each proton and neutron has a mass of one amu. Electrons are so much smaller
than protons and neutrons, their mass is ignored. So, the Atomic Mass is equal to the
number of protons plus the number of neutrons.
Page 1
ATOM BUILDING ACTIVITY:
Today we are going to explore the Periodic Table and build atoms of biologically important elements:
Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous, and Sulfur.
Directions:
1. Log into the computer and go to
http://www.pbslearningmedia.org/resource/nvhescichemistryelements/nova-elements/
2. Scroll down the page a little bit and click “LAUNCH”
3. After the App is loaded, listen to the Introduction, then click on “Explore the Interactive Periodic
Table”
4. Listen to the narration or click on “Instructions”. You can choose to explore any element by clicking
directly on the Periodic Table.
5. First, read and record important facts about the element by tapping on the element. Record in the
worksheet on page 3 & 4. Then, click on the “i” button at the top right to find the Symbol, Atomic
Number, and Atomic Mass (Weight) of the element. Record this information in your table on page
5.
6. Next, click the green “Build” button to bring you to the Atomic Sandbox. Listen to the narration, or
click “Instructions”, before building your atom. You will build the following element: Chlorine.
Fill in the far right column in the chart on page 5.
Page 2
Name: ______________________
ATOM BUILDING ACTIVITY WORKSHEET:
1. Carbon: Carbon is the __________ most abundant element in the universe. It is
the ___________ element capable of forming the complex _________________
structures on which all _____________
_______________ are based.
2. Hydrogen: Hydrogen is the _________ abundant element in the universe. It
makes up ___________ percent of the atoms and _____________ percent of
the mass.
3. Nitrogen:Nitrogen is the ______ most abundant element in the universe. All
_________________ on earth contain Nitrogen.
Page 3
4. Oxygen: Oxygen is the ____most abundant element in the universe. O2 is
essential for ___________________ and is a by-product of
_____________________________.
5. Phosphorous: Phosphorous is never found in its elemental form in nature due to
its highly ______________ nature. It is essential for life and serves as a key
building block in ______________, ______________, and _____________
__________________.
6. Sulfur: Sulfur is a naturally occurring element often found around
___________________ ___________ and ________________________. Sulfur
is a key component in ____________________ and is largely responsible for
their ________________
_____________________.
Page 4
Your element
Carbon
Hydrogen
Nitrogen
Oxygen
Phosphorus
Sulfur
Atomic #
Atomic Mass
(rounded)
# Protons
# Neutrons
TOTAL
#Electrons
# of e- on the
outer Shell =
the # of valence
e# of e- Shell
Page 5