2.  Dalton’s Atomic Theory and other important scientists RutherfordGoldstein ThomsonGell-Mann BohrChadwick SchrodingerDemocritus Millikan

3.  An element has an atomic number of 76. What is the number of protons and electrons in a neutral atom of this element?

4.  How is the number of neutrons in the nucleus of an atom calculated? Write a formula representing the number of neutrons in the nucleus.

5.  All atoms of the same element have the same _____.

6.  Isotopes of the same element have different _____.

7.  Using the periodic table, determine the number of neutrons in 16 O.

8.  What does the number 84 represent in the name krypton-84?

9.  Who discovered the neutron?

10.  Dalton’s Atomic Theory makes two assumptions that are incorrect. What are they?

11.  The element Indium has __ protons and ___ electrons.

12.  How do the isotopes of hydrogen-1 and hydrogen-2 differ?

13.  Why did J. J. Thomson reason that electrons must be a part of the atoms of all elements?

14.  What are the names of the following elements? 38 X and 39 X

15.  Describe the model of the atom as a result of Rutherford’s discovery of the nucleus. Draw a model showing the particles and their locations.

16.  The smallest particle of an element that retains the properties of that element is a(n) ____.

17.  How many protons, electrons, and neutrons does an atom with atomic number 50 and mass number 125 contain?

18.  An element called “X” has 10% of the isotope with a mass 55.11 amu, 20% of the isotope with mass 56.21 amu, and 70% of the isotope with mass 57.33 amu. Calculate the atomic mass of element X.

19.  How many protons are present in an atom of Beryllium-9?

20.  Calculate the number of neutrons in Lead-210.

21.  Determine the number of electrons in an atom of Iridium.

22.  Chlorine has two naturally occuring isotopes, Cl-35 has a mass of 34.9689 amu, and Cl-37 has a mass of 36.9659 amu. If chlorine has an average atomic mass of 35.4527 amu, what is the percent abundance of each isotope?