Aim What are valence electrons and how do

Aim: What are valence electrons and how do we draw Lewis Dot Diagrams? Do now: What is an ion of the atom with 5 protons and 6 electrons? What is an ion of the atom with 4 protons and 2 electrons? What is an ion of the atom with 7 protons and 7 electrons?

7. 1 Valence Electrons n n Valence electrons are the electrons in the highest occupied energy level of an element’s atoms. The number of valence electrons largely determines the chemical properties of an element.

7. 1 Valence Electrons n Electron dot structures are diagrams that show valence electrons as dots.

7. 1 The Octet Rule n n Noble gases, such as neon and argon, are unreactive in chemical reactions. In 1916, chemist Gilbert Lewis used this fact to explain why atoms form certain kinds of ions and molecules. He called his explanation the octet rule: In forming compounds, atoms tend to achieve the electron configuration of a noble gas.

7. 1 The Octet Rule n n Atoms of metals tend to lose their valence electrons, leaving a complete octet in the next-lowest energy level. Atoms of some non-metals tend to gain electrons or to share electrons with another nonmetal to achieve a complete octet.

Learning Check Draw Lewis Dot Diagrams for the following elements: P, Se, Cl, Kr, Sr, Cs, Na, O, Al, Ge, Mg

Demo n n n Sodium Potassium http: //www. youtube. com/watch? v=m 55 k gy. Ap. Yr. Y