1. Isotopes & Ions (Atomic Structure - Take 2)

2. Quick Recap Remember: Atomic number equals the number of ________. protons The number of protons equals the number of _________. electrons The atomic mass equals the ________ plus _________. protonsneutrons

3. What happens if… If you change the number of _________, you change the _________. protons element Can you change the number of _________ and still be the same element? electrons Yes! An atom with an unequal number of protons and electrons is called an _____. ion

4. Ions Ions have the same number of _______ but a different number of _________. protons electrons This makes an ion a ________ particle, since we don’t have the same number of ________ and _________. charged protonselectrons

5. Ion Symbols Ion symbols contain the ________ symbol and the ______ of the ion. element charge Here’s the hard part: Electrons have a _________ charge – so if you _____ electrons, you will have a _________ charge on your atom! negative gain negative

6. Calculating Charge The easiest way to figure out the charge on your ion is to ____ up the number of _______ and _________. add protonselectrons A chlorine atom gains an electron. What is the charge on the ion? Cl 17 35 +1 e - = +17 P -18 e - - 1 Cl -1

7. What happens if…? What happens if you _____ an electron?lose You will become a _________ ion!positive Na 11 23 - 1 e - = +11 P -10 e - +1 Na + 1

8. The more you lose… What happens if you lose more than one electron? Ca 20 40 - 2 e - = +20 P - 18 e - +2 Ca +2

10. What happens if… Can you change the number of _________ and still be the same element? neutrons Yes! Atoms of the same ________ that have different numbers of _________ are called _________. element neutrons isotopes Let’s look at an example…

11. Isotope Examples CC 12 66 14 What are the differences between these two atoms of carbon? 1. Different atomic masses 2. Different numbers of neutrons

12. What does it mean? Changing the number of neutrons changes the ______ of the atom, but not its _______ ________ or __________. mass Atomic number identity Isotopes occur ___________ -- this is the reason that the atomic mass listed on the Periodic Table is a _________. naturally decimal

13. Atomic Mass The atomic mass on the Periodic Table is actually an ________ of all the naturally-occurring _________ of that element. average isotopes When we use the atomic mass from the Periodic Table, we will _______ to the nearest _______ number first. round whole

14. Isotope Calculations You can calculate the number of __________ the same way you do for regular atoms! neutrons Take the ____________ and subtract the number of _______ (the atomic ________) atomic mass protonsnumber You still have the same _______ because all isotopes have the same number of ________! element protons

15. Isotope Symbols Isotope symbols contain the element symbol and the atomic _____. mass C-14 C-13 C-12 O-16 O-17 O-18