1. Isotopes and Ions

2. Isotopes Atoms of the same element can have different numbers of neutrons. different mass numbers. called isotopes. Boron-10 ( 10 B) has 5 p and 5 n Boron-11 ( 11 B) has 5 p and 6 n 10 B 11 B

3. Symbols Contain the symbol of the element, the mass number and the atomic number.

4. Symbols Contain the symbol of the element, the mass number and the atomic number. X Mass number Atomic number

5. Naming Isotopes Put the mass number after the name of the element. carbon- 12 carbon -14 uranium-235

6. Symbols Find the – number of protons – number of neutrons – number of electrons – Atomic number – Mass Number – Name Na 24 11

7. Symbols Find the number of protons number of neutrons number of electrons Atomic number Mass Number Name Br 80 35

8. Symbols if an element has an atomic number of 34 and a mass number of 78 what is the number of protons number of neutrons number of electrons Complete symbol Name

9. Symbols if an element has 91 protons and 140 neutrons what is the Atomic number Mass number number of electrons Complete symbol Name

10. Symbols if an element has 78 electrons and 117 neutrons what is the Atomic number Mass number number of protons Complete symbol Name

11. 1. Isotopes are A.Atoms of the same element with a different number of neutrons. B.Atoms or groups of atoms with a positive or negative charge. C.Cations D.Anions

12. 2. The symbol for an isotope contains A.The atomic number on the top left and the mass number on the bottom left of the symbol. B.The number of electrons. C.Mice D.The mass number on top left and the atomic number on the bottom left of the symbol.

13. 3. When naming an isotope, A.The mass number comes before the element name. B.You just put the elements name. C.The mass number comes after the element name. D.You just put the mass number.

14. IONS IONS are atoms or groups of atoms with a positive or negative charge. Taking away an electron from an atom gives a CATION with a positive charge. Adding an electron to an atom gives an ANION with a negative charge. To tell the difference between an atom and an ion, look to see if there is a charge in the superscript! Examples: Na + Ca +2 I - O -2 Na Ca I O

15. Forming Cations and Anions A Cation forms when an atom loses one or more electrons. CATion: PAWSitive Na  Na + + e - An Anion forms when an atom gains one or more electrons. Anion: A Negative ION Cl + e-  Cl -

16. Forming Cations and Anions https://www.youtube.com/watch?v=0q5rP7w xrDk https://www.youtube.com/watch?v=0q5rP7w xrDk

17. Predicting Ion Changes In general metals (Na) lose electrons ---> cations metals (Na) lose electrons ---> cations nonmetals (Cl) gain electrons ---> anions nonmetals (Cl) gain electrons ---> anions

18. Learning Check – Counting State the number of protons, neutrons, and electrons in each of these ions. 39 K + 16 O -241 Ca +2 198 20 #p + ___________________ #n o ___________________ #e - ___________________