1. Copyright © 2012 InteractiveScienceLessons.com Isotope -Atoms of an element that have the same # of protons but a different # of neutrons

2. Copyright © 2012 InteractiveScienceLessons.com Mass # ___ Isotope -Atoms of an element that have the same # of protons but a different # of neutrons Carbon protonsneutrons 66 12 - 12 total number of particles In nucleus

3. Copyright © 2012 InteractiveScienceLessons.com Mass # ___ Carbon protonsneutrons 66 12 - 12 Mass # ___ Carbon protonsneutrons 67 13 - 13 total number of particles in nucleus Now you do Carbon-14. We’ll check in 1 minute.

4. Copyright © 2012 InteractiveScienceLessons.com Mass # ___ Carbon protonsneutrons 68 14 - 14

5. Copyright © 2012 InteractiveScienceLessons.com Isotope Notation There are several different ways to write symbols for isotopes, each of which is perfectly legitimate. The other ways to write each of these hydrogen isotopes from top to bottom are: Hydrogen-1 or H-1 Hydrogen-2 or H-2 Hydrogen-3 or H-3 Example Write down the three different notations for a carbon atom with 6 protons and 6 neutrons.

6. Copyright © 2012 InteractiveScienceLessons.com Isotopes: Atoms of the same element with different masses. Isotopes have different numbers of neutrons. They can be written like this: 11 6 C 12 6 C 13 6 C 14 6 C Or they can be written like this: C – 11 C – 12 C – 13 C – 14

7. Copyright © 2012 InteractiveScienceLessons.com H Hydrogen 1 1 Protons: 1 Neutrons: 0 Electrons: 1

8. Copyright © 2012 InteractiveScienceLessons.com Isotopes of Hydrogen

9. Copyright © 2012 InteractiveScienceLessons.com Hydrogen-1 Contains 1 proton and 1 electron – as all isotopes of H must contain. No neutrons The most common type of H atom.

10. Copyright © 2012 InteractiveScienceLessons.com Hydrogen-2, deuterium Contains 1 proton and 1 neutron in the nucleus.

11. Copyright © 2012 InteractiveScienceLessons.com Hydrogen-3, tritium Contains 1 proton and 2 neutrons in the nucleus.

12. Copyright © 2012 InteractiveScienceLessons.com Isotopes Chlorine exists as two isotopes, chlorine-35 and chlorine-37. Chlorine has the atomic number 17. Work out the number of neutrons in chlorine-35 and chlorine-37.

13. Copyright © 2012 InteractiveScienceLessons.com Isotopes Chlorine- 35 17 protons No. of neutrons = 35 – 17 = 18

14. Copyright © 2012 InteractiveScienceLessons.com Isotopes Chlorine- 37 17 protons No. of neutrons = 37 – 17 = 20

15. Copyright © 2012 InteractiveScienceLessons.com Drawing and Naming Isotopes Draw a Boron atom P = N = E = How do you name this atom? Draw a Boron isotope with a mass number of 13 P = N = E = How do you name this isotope?

16. Copyright © 2012 InteractiveScienceLessons.com Ion -an atom with a different number of ELECTRONS than protons before Sodium 11 p+ 11 N Na 11 + 11 - 0 Chlorine 17 p+ 17 N Cl 1 outer electron= unstable! 17 + 17 - 0 after 11 + 10 - +1 17 + 18 - Na +1 Cl -1

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