Non-Metals and Metalloids CHEMISTRY

Learning Goals  To be able to explain the properties of non-metals and metalloids within the periodic table

Properties of Non-Metals  Many are gases at room temperature, some are solids, one is a liquid  Solid non-metals have a dull lustre  Solid non-metals are brittle  Non-metals are usually poor conductors of electricity and thermal energy  Examples: carbon ( C ), oxygen ( O ), chlorine ( Cl ), and neon ( Ne )

Important Families  Non-metals are located on the right side of the staircase line  The last two groups are halogens (group 17) and noble gases (group 18)

Group 17 – Halogens  Members of the halogen family are highly reactive  Fluorine (F) is the most reactive of the halogens and non-metals  Pure chlorine (Cl), bromine (Br), and iodine (I) are poisonous to living things  Chlorine is used to disinfect water, and iodine solution is used to disinfect wounds  Iodine tablets are used by campers to make water from a stream or river safe to drink  These elements are commonly used in halogen lights

Group 18 – Noble Gases  Noble gases are generally unreactive  They are in the last group or column of the periodic table  Some noble gases are used to light neon signs because the gases give off brightly coloured light when electricity passes through them  Other uses include helium ( He ) for balloons and xenon ( Xe ) for some vehicle headlights

Halogens

Noble Gases

Metalloids

 Metalloids have properties in between those of metals and non-metals  All metalloids are solids at room temperature  Some metalloids are weak conductors of electricity and thermal energy  Examples: boron ( B ), silicon ( Si ), germanium ( Ge ), and arsenic ( As )

Metalloids and Computers  Metalloids are very useful to the electronic industry because they can conduct electricity to some extent  Silicon and germanium are used to make semiconductors, which are part of computer chips

Success Criteria  I CAN describe the properties of non-metals and metalloids  I CAN locate the halogens, noble gases and metalloids on the periodic table

To Do…  Video Demonstrations  Worksheet