Basic Atomic Structure Worksheet (You must use a Periodic Table of the Elements)

1. Define nucleon.

2. Define mass number, A.

3. Define atomic number, Z.

4. What are the relative masses of a proton, a neutron and an electron?

5. Describe how you calculate the number of neutrons of an isotope from its mass number(A) and its atomic number(Z).

6. The 3 particles of the atom are:

a. ______b. ______c. ______

Their respective charges are:

a. ______

b. ______

c. ______

2. The number of protons in one atom of an element determines the atom’s ______, and the number of electrons determines the ______of the element.

3. The atomic number tells you the number of ______in one atom of an element. It also tells you the number of ______in a neutral atom of that element. The atomic number gives the “identity” of an element as well as its location on the periodic table. No two different elements will have the ______atomic number.

4. The ______of an element is the average mass of an element’s naturally occurring atom, or isotopes, taking into account the ______of each isotope.

5. The ______of an element is the total number of protons and neutrons in the ______of the atom.

6. The mass number is used to calculate the number of ______in one atom of an element. In order to calculate the number of neutrons you must subtract the ______from the ______.

7. Given the elements name and its mass number give the complete isotopic symbol and the number of neutrons for the following:

Lithium-6 ______

Iron-58 ______

Oxygen-17 ______

Krypton-78 ______

Bromine-79 ______

Copper-65 ______

Mercury-200 ______

Helium-3 ______

8. Give the element symbol of and the number of electrons in a neutral atom of:

Uranium ______

Boron ______

Chlorine ______

Iodine ______

Xenon ______

9. Name the element which has the following numbers of particles:

a. 26 electrons, 26 protons ______

b. 53 protons, 74 neutrons ______

c. 2 electrons (neutral atoms) ______

d. 20 protons ______

e. 86 electrons, 125 neutrons, 82 protons ______

f. 0 neutrons ______

10. If you know ONLY the following information can you ALWAYS determine what the element is? (Yes/No)

a. Number of protons ______

b. Number of neutrons ______

c. Number of electrons in a neutral atom ______

d. Number of electrons ______