1. Mixed Groups

2. Properties of Metalloids Metalloids – form ionic and covalent bonds with other elements and can have metallic and nonmetallic properties Metalloids will generally conduct electricity better than nonmetals but not as good as metals – giving them the name semiconductor Metalloids are found along the stair-step line (exception of aluminum) – found in groups 13, 14, 15, 16, and 17

3. Boron group Group 13 Has 3 valence electrons (valence electrons – the electrons in the outermost shell of the atom) Important element Aluminum – most abundant metal in Earth’s crust Strong and light – used in construction of airplanes

4. Carbon Group Group 14 4 valence electrons Important elements All organic compounds contain Carbon but not all carbon compounds are organic Silicon – second most abundant element found in Earth’s crust (most found as sand SiO 2 )

5. Allotropes Allotropes – are different forms of the same element having different molecular structures

7. The Nitrogen Group Group 15 5 valence electrons Each breath you take is about 80 percent gaseous nitrogen.

8. The Oxygen Group Group 16 Oxygen makes up about 21% of air… exists as a diatomic molecule (diatomic molecule – a molecule that consists of two atoms of the same element) – O 2

9. Synthetic Elements Elements scientists have made by smashing existing elements with particles.

10. Classwork/Homework Page 596-597 Write and answer questions 1-15