Section 3: Metals

• Objectives:describe chemical and

physical properties of metals

identify and describe different kinds of metals, and compare the properties of the various families of metals

Copper wire is very ductile

•Gallium has a low melting point

Physical Properties of Metals

• malleable– describes material

that can be pounded or rolled into shape.

• ductile– describes material

that can be pulled out into a long wire.

• conductor– substance that electrons

move freely, transmits heat or electricity.

• magnetic– metals that are attracted to

magnets and can be made into magnets.

-only iron, cobalt and nickel are naturally magnetic

Chemical Properties of Metals

• corrosion– gradual wearing

away of a metal element caused by chemical reaction.

•Metals show wide range of chemical properties•From very reactive (Groups 1 and 2)•unreactive(gold and chromium)•corrosive

Alloysalloy

–substance made of two or more elements, at least one of which is a metal, that has the properties of metal.

Alkali Metals

• elements in Group 1• Only found as a compound in

nature BECAUSE:– Very reactive

-have 1 valence electron• Easily transferred to another atom

• Very soft and shiny– Can be cut with plastic knife

•Sodium is less dense than water so it appears to dance when in contact with the water.

Alkaline Earth Metals

•elements in Group 2•Less reactive than Group 1 more than most•Only found as compound in nature•Very Reactive

BECAUSE-Has 2 valence electrons -has unstable valence shell

•magnesium

magnesium metal ribbon

•magnesium ribbon burning

Transition Metals•An element in Group 3 through 12 of the

periodic table.

•Have one or two electrons in outer energy level.•Less active than Groups 1 and 2 (Don’t easily give up valence electrons.)

Lanthanide and Actinide• lanthanide

– A group of element in the first row of the rare earth elements in the periodic table.

– Soft, malleable, shiny metals with high conductivity

• actinide– A group of elements in the second row of the rare earth elements in the

periodic table.– All are radioactive, because are unstable– After 92 all elements are man made

Yetterbium•Usually, very small amount of Yb is used; either small sample of radioactive isotope as source of x-rays

• Neodymium• Neodymium magnets are the strongest • permanent magnets known

(compound ---Nd2Fe14B). Used in microphones, professional

loudspeakers, in-ear headphones, guitars and computer hard drives where low mass, small volume, or strong magnetic fields are required. •Neodymium is used for coloring glass to make welder's and glass-blower's goggles.

FYI: FOR YOUR INFORMATION

Lanthanide Element examples: