CLASS COPY
Build an Atom Understanding Check
1. Build an atom in the box below that has the following components:
3 protons P
4 neutrons N
3 electrons E
3P
4N
2.
Which element this atom is on this periodic table below: Lithium (Li)
3.
How many electrons in the first electron level? 2
How many valence electrons for this atom? 1
4. The atomic mass of this atom is: 7 AMU
a.
b.
c.
d.
5.
3 amu
4 amu
6 amu
7 amu
Explain what ideas you used to choose an answer:
Atomic mass = to the # of PROTONS plus the # of NEUTRONS.
The charge of this atom is: 0 (NEUTRAL)
a.
b.
c.
d.
e.
0, this is a neutral atom
-3
-1
+1
+3
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CLASS COPY
You start with an atom made of:
3 protons
4 neutrons
3 electrons. You want to change
your atom’s properties by adding or removing sub-atomic particles (protons, neutrons and electrons.
For each question below, mark YES if a change will work, and mark NO if it will not work.
6.
If you want to change the type of element your atom is, you can either:
Add a proton
Yes
Add a neutron
No
Add an electron
No
Remove an electron
No
Explain the ideas you used to choose your answer:
The number of protons determine the type of atom or element it is.
7. If you want to change the charge (make it an ion) of your atom, you can:
Add a proton
No
Add a neutron
No
Add an electron
Yes
Remove an electron
Yes
Explain the ideas you used to choose your answer:
When an atom gains or losses electrons the overall charge of the atom changes
(becomes a positively or negatively charged ion). If you change protons you change
the element.
8. If you want to change the mass of your atom by 1 or more amu (atomic mass units), you can:
Add a proton
Add a neutron
Add an electron
Remove an electron
Yes
Yes
No
No
Explain the ideas you used to choose your answer:
The electrons contribute very little to the mass of the atom. The atomic mass of
each atom is the result of the PROTONS and the NEUTRONS.
If you add 1 proton and 1 neutron to an atom of Beryllium (Be)…
9. Will the element be Lithium, Beryllium, Boron or Carbon? BORON
10. Will the mass change? Yes If so, what is the new mass of the atom? 11
11. Will the charge change? Yes If so, what is the new charge of the atom?+1 (no electron was added)
12. How many valence electrons does this atom have? 2 Boron should normally have 3 valence
electrons, but the question only stated that Be had 1 proton and 1 neutron added (no
electrons).
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