Name ________________________
● Atoms, Elements, & the Periodic Table
BUILD AN ATOM INTRO
In this intro activity, you will explore the atom using a computer simulation.
Part I - Explore the Atom (6 marks)

Open the Build an Atom Simulation - click on the
link (https://phet.colorado.edu/sims/html/buildan-atom/latest/build-an-atom_en.html).

Click on the Atom option on the first screen

Click on the green plus sign next to Net Charge

Click on the green plus sign next to Mass Number
Atoms are made of three subatomic particles - protons,
neutrons, and electrons. The atom has two main parts - the
nucleus and the orbits (which are also called the electron
clouds)

Drag a proton onto the atom. Where does it go?

Drag a neutron onto the atom. Where does it go?

Drag an electron onto the atom. Where does it go?
What subatomic particles (protons, neutrons, and/or electrons) are found in the nucleus of an atom?
What subatomic particles (protons, neutrons, and/or electrons) are found in the obits?
What element did you make when you added one proton, one neutron, and one electron?

Add another proton to the atom that you made. What changes?

Add another neutron to the atom that you made. What changes?

Add another electron to the atom that you made. What changes?
What subatomic particle (proton, neutron, or electron) is responsible for determining the identity of an
atom?
What subatomic particles (protons, neutrons, and/or electrons) are responsible for determining the mass
number of an atom?
What subatomic particles (protons, neutrons, and/or electrons) are responsible for determining the net
charge of an atom?
Part II - Building Atoms of Elements (2.5 marks)

Build the following atoms of elements. When each one is complete, record the protons, neutrons,
and electrons in it, determine the identity of the element, and use colored pencils or markers to draw
it on the model given.
Directions
Example
 Add 1 proton
Subatomic Particles
What Element
p=1

Add 1 neutron
n=1

Add 1 electron
e=1
Hydrogen
H
Diagram
Directions
Subatomic Particles

Add 5 protons
p=

Add 6 neutrons
n=

Add 5 electrons
e=

Add 3 protons
p=

Add 4 neutrons
n=

Add 3 electrons
e=

Add 10 protons
p=

Add 10 neutrons
n=

Add 10 electrons
e=

Add 9 protons
p=

Add 10 neutrons
n=

Add 9 electrons
e=

Add 6 protons
p=

Add 6 neutrons
n=

Add 6 electrons
e=
What Element
Diagram
Part III - Identifying Atoms of Elements (1.5 marks)

Give the mass number and Identify the elements given their diagrams and subatomic particles.
Diagram
Subatomic Particles
p=4
n=5
e=4
p=7
n=7
e=7
p=8
n=8
e=8
Mass Number
What Element
Part IV: Isotopes (5 marks)

Test your understanding of isotopes by examining the relationships between the pairs of
atoms listed below:
Atom 1
Atom 2
12
6
13
6
C
Carbon-12
Argon-40
11
5
B
An atom with 13
protons and 13
neutrons

C
12
6
C
Argon-41
Boron-10
An atom with 14 protons
and 13 neutrons
Relationship between atom 1 and atom 2
Isotopes
Same Atom, Not Isotopes of Each Other
Different Element
Isotopes
Same Atom, Not Isotopes of Each Other
Different Element
Isotopes
Same Atom, Not Isotopes of Each Other
Different Element
Isotopes
Same Atom, Not Isotopes of Each Other
Different Element
Isotopes
Same Atom, Not Isotopes of Each Other
Different Element
The periodic table has a great deal of information about every atom. Using your periodic table,
answer the following questions:
a) What is the atomic number of chlorine (Cl)? _____
b) What is the atomic number of tungsten (W)? _____
c) How many protons are there in any Cl atom? _____
d) How many protons are there in any Te atom? _____

Build any element that you want for this final section of this activity, and fill in the information
below:
a.
b.
c.
d.
e.
f.
Number of protons _____
Number of electrons _____
Number of neutrons _____
Atomic Mass ______
Atomic Number _______
Charge _______