Ch. 19 section 1 ppt--Metals-2

Ch. 19

Elements and their Properties

Properties of Metals

• _{Good conductors of heat and electricity.} • _{All but one (mercury) are solid at room}

temperature.

• _{Metals reflect light—a property called luster.} • _{Metals are malleable – which means they can}

be hammered or rolled into sheets.

• _{Metals are ductile – they can be drawn into}

Malleability

Ductility

Ionic Bonds

• _{The atoms of metals tend to have 1-3 electrons in}

their outer energy levels. Metals tend to give these electrons up easily in chemical bonding because of the strength of the charge of the protons in the nucleus. This forms a positive ion – charged atom that has

fewer electrons than protons.

• _{Ionic bond – attraction formed between oppositely}

charged ions in an ionic compound.

• _{Metals tend to form ionic bonds with non-metals and}

Metallic Bonding

• _{Positively charged metallic ions are surrounded by a}

cloud of electrons. Outer level electrons move

freely around the positively charged ions of metal.

• _{This explains many of the properties of metals:}

conduction of electricity (electrons moving from ion to ion in the cloud) and malleability (metal is

The Alkali Metals

• _{The elements in group 1 of the periodic table.} • _{Most reactive of all metals and softest.}

• _{React rapidly and almost violently with oxygen}

and water.

• _{One electron in its outer shell which is given up}

when it combines—resulting in a positively charged ion.

• _{Not found in nature by themselves—always in a}

Uses of Alkali Metals

• _{All living things need potassium and sodium}

compounds to be healthy.

• _{Lithium compounds are used to treat bipolar}

disorder.

• _{Photocells require rubidium or cesium.}

• _{Francium is rare and a radioactive element –}

The Alkaline Earth Metals

• _{Group 2 on the periodic}

table.

• _{Not found alone in}

nature because, like the alkalis, also highly

reactive.

• _{2 electrons to give in}

Uses of Alkaline Earth Metals

• _{Magnesium produces the bright white in fireworks.}

Magnesium is light and strong—used in cars, airplanes, spacecraft, ladders, baseball/softball bats. Important element in chlorophyll and photosynthesis.

• _{Strontium produces the red flashes in fireworks.} • _{Calcium is found in calcium carbonate and calcium}

phosphate — compounds needed for shells of living things and bones.

• _{Barium is used in medical diagnostics because it absorbs}

x-rays so doctors can see inside the digestive tract.

Transition Elements

• _{Groups 3-12 on the}

periodic table.

• _{Commonly occur in nature}

as uncombined elements.

• _{Often form colored}

Iron, Cobalt, Nickel

• _{Referred to as “The Iron Triad” because they are used} together to create steel and other metal mixtures.

• _{Iron--the main component of steel--is the most} widely used of all metals. Magnetic!

• _{Nickel gives strength and a shiny, protective coating} to other metals.

Copper, Silver, and Gold

• _{Coinage metals (historically used to make coins).}

Copper and nickel are used to make coins today.

• _{Copper is an excellent conductor of electricity and is} used to make wires.

• _{Silver compounds break down when exposed to light} producing an image and are used to make

photographic film and paper.

Zinc, Cadmium and Mercury

• _{Group 12 on the periodic table.}

• _{Zinc combines with oxygen in the air to form a}

thin protective coating of zinc oxide on its surface. Used to coat the surfaces other metals.

• _{Cadmium is used in rechargeable batteries.}

• _{Mercury is liquid at room temp. and is used in}

The Inner Transition Metals

• _{Fit in between groups 3 and 4 in period 6 and 7}

on the table.

• _{Lanthanides – First row, elements with atomic}

numbers 58-71. These follow the element lanthanum.

• _{Actinides – The second row of the transition}

elements that follow the element actinium. Atomic # 90-103. All are radioactive and

Ores: Minerals and mixtures

• _{Metals in the earth’s crust that are combined}

with other elements are found as ores. • _{The ore is mined and separated from the}

Nonmetals

• _{Approximately 96% of your body’s mass is}

made up of carbon, hydrogen, oxygen and nitrogen—nonmetals!

• _{Nonmetals – are elements that are usually}

gases or brittle solids at room temperature.

• _{Most nonmetals do not conduct heat or}

Bonding in Nonmetals

• _{The electrons in nonmetals are strongly attracted}

to the nucleus and aren’t lost easily, so they don’t conduct electricity well.

• _{Nonmetals form ionic bonds with metals, taking}

electrons (PbS = lead sulfide). They form covalent

bonds with other nonmetals and share electrons (CO₂).

Galena is PbS

Hydrogen

• _{A diatomic molecule – consists of two}

atoms of the same element in a covalent bond. Hydrogen is a diatomic gas if not combined with another element.

• Hydrogen is highly reactive, with a single electron that combines easily with other elements (especially oxygen to make

water).

• _{Hydrogen means “water forming” in Greek.} • _{Hydrides – compounds formed with}

Halogens

• _{Group 17 on the periodic table—fluorine, chlorine,}

bromine, iodine, astatine. Seven electrons in the outer shell, very reactive.

• _{Form diatomic covalent molecules in gaseous state.}

Distinctive colors: Chlorine = greenish yellow, bromine = reddish orange, iodine = violet.

• _{Fluorine is the most chemically active of all elements}

(hydrogen fluoride).

• _{Chlorine is used to disinfect water (bleach).}

• _{Iodine is used to disinfect wounds and is essential in}

Goiter (above) is an enlargement of the thyroid gland.

The Noble Gases

• _{They exist as isolated atoms and are very}

stable—no naturally occurring compounds because they are nonreactive. Their outer electron orbitals are full.

• _{Uses – helium is lighter than air and is used in}

balloons and blimps to float. Neon and argon are used in “neon” lights for advertising.