Nonmetals Metalloids 2252013 Nonmetals Dull not lustrous Brittle

Nonmetals & Metalloids 2/25/2013

Nonmetals Dull (not lustrous) Brittle and break into pieces (not malleable or ductile) Do not conduct heat or electricity well Many are gases rather than solids

Common Nonmetals - Hydrogen (H) Colorless & Odorless Gas Explosive/Highly Flammable Light Part of Water (H 2 O)

Common Nonmetals - Nitrogen (N) Colorless & Odorless Gas Makes up 80% of Earth's atmosphere Bacteria change nitrogen in the soil into nitrogen compounds → plants change them into proteins your body can use Nitrogen + Hydrogen combine into ammonia (in cleaners) Put into fertilizers for plant growth Contributes to acid rain (nitric acid)

Common Nonmetals - Carbon Found in all living things and fossils Present in fossil fuels such as coal and petroleum Solid

Common Nonmetals - Oxygen Colorless, Odorless Gas Supports burning (but is non-explosive) Necessary for respiration Transported throughout your body in the circulatory system (iron-containing hemoglobin in your blood transports oxygen to your body cells) Easily combines with other elements to form oxides Present in water (H 2 O) Ozone layer is made of a form of oxygen

Metalloids Metalloids are elements that have properties of both metals and nonmetals. All metalloids show metallic luster (reflect light and are shiny). 8 metalloids total (we will focus on Silicon)

Metalloids – Silicon When combined with oxygen, silicon forms sand. . . when sand is melted and allowed to cool, it forms glass Comes in shiny gray chunks that look like a metal BUT the chunks are rough and full of little holes Silicon breaks apart easily, but does conduct electricity

Metalloids – Silicon makes up ¼ of the Earth's crust Pure silicon is a semiconductor, used in circuits and electronic devices Glass (including optical fibers) is a silicon compound Ceramic tiles made of silica on the outside of spacecraft protect them from heat during reentry