This document discusses atomic bonding and valence electrons. It begins by explaining that the outermost shell of electrons in an atom are valence electrons, which are loosely held and key to chemistry. All atoms seek to attain a full outer shell. Electron dot diagrams are introduced to represent the valence electrons of different elements. Hydrogen has 1 valence electron, carbon has 4, and oxygen has 6. The document then discusses how magnesium and iodine will gain or lose electrons to attain a full shell. It notes that atoms bond by trading electrons to form chemical bonds. A review section defines related atomic structure terms like atomic number, period, and group. Nonmetals are noted to have 4 or more valence electrons and can bond by gaining electrons from

1. Atomic Bonding Page 12

2. Valence Electrons Outer most shell of electrons Held loosely to an atom Key to all chemistry All atoms want to have full shells 12

3. Electron Dot Diagrams H C O Use the symbol for each element with a dot for each outer electron. Identify each element and the number of valence electrons that it has. Hydrogen 1 Carbon 4 Oxygen 6 13

4. Magic game of

5. Bonding I (At #53) has how many valence electrons? What will it do to fill its shells? Mg (At #12) has how many valence electrons? What will it do to fill its shells? Atoms always to the easiest thing! Mg will always lose 2 electrons never gain 6 7 Gain 1 electron 2 Gain 6 or lose 2 electrons 13

6. Bonding Where do extra electrons go? Where can atoms find the electrons they need? Atoms trade electrons = Chemical bond *The fewer electrons you need to trade the more reactive the atom will be! When atoms bond, new substances are made. 13

7. Review How are element represented in the periodic table? By symbol The ____________ of an element is the number of protons in the nucleus of the atom What is a row of elements across the table called? Period Describe how the atomic number changes across a period of elements. Each element increases by 1 atomic number atomic number 14

8. Review What are the elements in the same column called? Group or family Elements within a group always have the same number of Valence Electrons 16

9. Nonmetals How many valence electrons do non-metals have 4 or more Describe two ways that non-metals can combine with other elements. Combine with metals to gain electrons Combine with other non-metals to share electrons 19