Metals, Nonmetals, and Metalloids

What two types of properties are typically used to describe something?

 Physical  Chemical

How would you describe a metal?

Physical properties  Shininess  Malleability  Malleable material can be hammered or rolled into flat shapes  Ductility  ductile material can be pulled out into wire  Conductivity: ability to transfer heat or electricity

Chemical properties  how reactive something is  Reactivity: ease and speed that an element combines with other elements  Metals usually react by losing electrons to other atoms  Very reactive metal: sodium  Not very reactive: platinum, gold

Reactivity of metals  Most metals fall in the middle of sodium and gold  Example: iron reacts slowly with oxygen  What does it form?  This is corrosion: gradual wearing away of a metal due to a chemical reaction

Groups of metals  Columns in the periodic table  Metals in the same group have similar properties  Reactivity tends to decrease as you move left to right across periodic table

Important metal groups  Alkali metals  Alkaline earth metals  Transition metals  Metals in mixed groups  Lanthanides  Actinides

Assignment  Read the section about your assigned group of metals (p )  Come up with a way to teach the important facts about this group to the class  Where it is on periodic table  Properties (chemical and physical)  Well-known examples and possible uses  Possible ways to present: poster, song, skit, PowerPoint, brief presentation

Synthetic elements  Atomic numbers > 92  Not found naturally on Earth – made when nuclear particles are forced to crash into each other  Particle accelerators: machine that moves nuclei of atoms faster and faster until the crash into one another and combine into one nucleus  The greater the atomic number, the more difficult the element is to synthesize

Nonmetals  16 of them  Poor conductors of heat and electricity  Reactive  10 gases, 5 solids, 1 liquid  2 gases make up most of the air we breathe: can you name them?

 Nitrogen  Oxygen

 One nonmetal is liquid at room temperature: can you name it?

 Bromine (Br)

Solid nonmetals  Dull (not shiny)  Brittle (not ductile or malleable)

Chemical properties  Most nonmetals are reactive (form compounds easily)  Flourine (F) is most reactive element known

Families of nonmetals  Carbon family  Nitrogen family  Oxygen family  Halogen family  Noble gases  Hydrogen (not a family)

 What group is your family?  2-3 most important things you read about this family  Present these facts in the most interesting way possible so your classmates can remember them!