1. Rutherford Experiment & Isotopes Mr. Rana 9/21/12

2. Bell Ringer 1. What are isotopes? 2. What is the mass number of Uranium – 238 (atomic number = 92)? What is the atomic number? 3. How many neutrons does Uranium-238 have (atomic number = 92)?

3. 1.1f – Students will understand that isotopes have the same number of protons but different numbers of neutrons.

4. Isotopes have almost identical physical and chemical properties, but have different _____________ in nature.

5. Isotopes have almost identical physical and chemical properties, but have different numbers of neurons in nature.

6. 1.1g – Students will understand how to calculate the number of neutrons from the atomic number and the mass number

7. The _____________ is the number of protons in the nucleus of an atom. The _____________ is the total number of protons and neutrons in an atom. _______________ are atoms that have the same number of protons, but different numbers of neutrons

8. The atomic number is the number of protons in the nucleus of an atom. The mass number is the total number of protons and neutrons in an atom. Isotopes are atoms that have the same number of protons, but different numbers of neutrons

9. 1. Notation with atomic number, mass number, and chemical symbol: Example There are several ways to represent isotopes

10. 2. Notation with just mass number and chemical symbol:

11. 3. Notation with mass number and name: Example Name-Mass Number Carbon-14

12. 4. Write the following elements in isotope notation. a.16 protons, 18 neutrons, 16 electrons b.11 protons, 12 neutrons, 11 electrons c.20 protons, 20 neutrons, 20 electrons