Name____________________
Computer Lab on Atoms and Isotopes
Go to google.com and search atoms. Click on the link that says “All About Atoms- What are atoms?”
http://education.jlab.org/atomtour/index.html
Read the “What are atoms?” section and answer the following short answer questions:
1- What do atoms make up?
2- How many naturally occurring kinds of atoms are there?
Now click on “Click here to continue”.
Navigate through the Protons, Neutrons, Nucleus, Electrons, and Fun Facts sections and answer the short answer questions that
follow:
3- What is the charge on a proton?
4- What is the charge on a neutron?
5- What two types of particles make up the nucleus?
7- When was the nucleus discovered?
6- Where is the nucleus located on an atom?
8- What is the charge on an electron?
9- What two particle types have almost the same mass (Circle two of the following: protons, electrons, and neutrons)?
10- Draw a helium atom and label each particle type:
Now Google search “Isotopes” And click on the link that says Chem4Kids.com.
http://www.chem4kids.com/files/atom_isotopes.html
Read the first paragraph Neutron Madness to answer the following questions:
11.) If an atom is missing a neutron or has an extra neutron it is called an ______________.
12.) Even though an isotope has lost or gained neutrons, is it still the same element? ________
13.) As shown in the pictures, C—12 is a Carbon atom with _____________ Neutrons (the green circles).
14.) As shown in the pictures, C—14 is a Carbon atom with _____________ Neutrons.
15.) C—12 and C—14 are isotopes of one another, because they have a different number of Neutrons (the green dots), but the
same number of _______________ (the blue dots).
16.) The 12 in the C—12 is the Mass Number of this atom. Look at the picture of C—12 and decide whether the Mass
Number means: A. The number of protons B. The number of neutrons C. The number of Protons PLUS the number of
neutrons.
17.) Make a drawing similar to the drawings of isotopes on this web-page to show the following two isotopes: Li—4 and
Li—5.
(Li has three protons) (Use 0 circles as neutrons, and use + circles as protons)
Now Read the second paragraph Messing with the Mass to answer the next questions:
18.) On the periodic table, the atomic mass of an element is rarely an ___________ number. That happens because of the
______________________.
19.) Atomic masses are calculated by figuring out ____________________________________ are out there in the universe.
20.) For Carbon, there are a lot of C—12, a couple C—13, and a few C—14 atoms. When you _______________ out all of the
masses, you get a number that is a little bit higher than _______.
21. Why do we put average atomic masses on the periodic table rather than exact, even numbers? (look at the last sentence in
this paragraph for a huge clue)
_________________________________________________________________________
22. Steve Hall discovers a new element that he names Marshall Schools (Ms). Steve Hall determines that in the universe there
are an equal number of Ms—14 atoms, Ms—15 atoms, and Ms—16 atoms. What will the periodic table list for the atomic mass
of Ms? A. 14.00
B. 15.25 C. 15.00 D. 16.67
23. Steve discovers a new element he calls Chemistry. The distribution of this element in the universe is as follows:
Chemistry—2 (25%) Chemistry—3 (25%) Chemistry—4 (50%). What will the periodic table list as the atomic mass?
A. 4.00 B. 5.00 C. 2.00 D. 3.90
E. 3.25 F. 3.00
Google Search “Interactive Periodic Table” and click on the first link (www.chemicalelements.com) Then, click on N on
the periodic table (Nitrogen).
24. Scroll down to the picture of a Nitrogen Atom. How many Protons does Nitrogen have? _______________
25. The number of protons that nitrogen has is called its: A. Atomic Number B. Mass Number C. Atomic Mass
26. How many Neutrons does Nitrogen have? _____ 27. How many Electrons does Nitrogen have? _______
28. Valence Electrons are the electrons in the very outer electron shell. How many Valence Electrons does Nitrogen have? ____
29. Scroll down to the Facts section on Nitrogen to answer this question: where is lots of Nitrogen found on earth?
______________________________________________
Now go back on your browser and click on P (Phosphorous) Scroll down to the picture of a Phosphorous atom.
30. The Phosphorous atom has how many valence electrons? _______________
31. How many neutrons? ____________________
32. How many protons? ____________________
33. Add the number of protons plus the number of neutrons to find out the exact mass of the atom: A. 30 amu B. 31 amu C.
32 amu
34. Therefore, the atomic mass of an atom is: A. All the stuff in the Nucleus (protons + neutrons)
electrons
B. Only protons and