Build An Atom Worksheet:
http://phet.colorado.edu/sims/html/build-an-atom/latest/build-an-atom_en.html
Answers
Instructions:
After completing each
of the following steps, fill out the
information in that row.
Name of element
Symbol
Stable?
(yes/no)
Charge
(-,0,+)
Mass
Number
Atomic
Number
Number of
Protons
Number of
Neutrons
Number of
Electrons
1. Select “Symbol” and drag a red
proton to the yellow “X” (nucleus)
Hydrogen
H
Yes
+1
1
1
1
0
0
2. Drag a gray neutron to the
Hydrogen
H
Yes
+1
2
1
1
1
0
3. Drag a blue electron to the first
orbit. (Make sure “Orbits” is
selected for Model)
Hydrogen
H
Yes
0
2
1
1
1
1
4. Add another proton to the
Helium
He
Yes
+1
3
2
2
1
1
5. Add a neutron.
Helium
He
Yes
+1
4
2
2
2
1
6. Add another neutron.
Helium
He
No
+1
5
2
2
3
1
7. Add an electron.
Helium
He
No
0
5
2
2
3
2
8. Add another electron.
Helium
He
No
-1
5
2
2
3
3
9. Add a proton.
Lithium
Li
Yes
0
6
3
3
3
3
10. Add another proton.
Beryllium
Be
No
+1
7
4
4
3
3
nucleus.
nucleus.
Continue to add protons, neutrons, and electrons until you feel that you understand the relationships between the columns in the table above. Then circle the correct
italicized term(s) in each sentence on the following page.
© Copyright 2014 – All rights Reserved www.cpalms.org Created By Amy D. Alford
1. The addition or removal of (protons, neutrons, electrons) causes the element name to change.
2. Atomic number is equal to the number of (protons, neutrons, electrons).
3. Atomic mass is equal to the number of (protons, neutrons, electrons) plus the number of (protons, neutrons, electrons). It doesn’t matter
which order as long as protons and neutrons are circled.
4. An atom becomes unstable when there are too many or not enough (protons, neutrons, electrons). Atoms of the same element with
different numbers of neutrons are called isotopes.
5. An atom becomes charged when the number of (protons, neutrons, electrons) does not equal the number of (protons, neutrons,
electrons). It doesn’t matter which order as long as protons and electrons are circled. A charged atom is called an ion.
6. As you add protons, what pattern do you notice about the periodic table?
A) The elements are ordered from right to left across the periodic table by increasing atomic number.
B) The elements are ordered from left to right across the periodic table by increasing atomic number.
C) The elements are ordered from right to left across the periodic table by increasing atomic mass.
D) The elements are ordered from left to right across the periodic table by decreasing atomic mass.
7. (Protons, neutrons, electrons) are found only in the nucleus of an atom. (Choose two.)
8. (Protons, neutrons, electrons) are found only in the electron cloud.
9. Only (one, two, three) electrons could fit in the first inner orbit.
10. Bonus: How many electrons can fit in the second orbit? 8
11. © Copyright 2014 – All rights Reserved www.cpalms.org Created By Amy D. Alford