Metals Most elements are metals. 88 elements to the left of the stairstep line are metals or metal like elements.

Physical Properties of Metals: Luster (shininess) Good conductors of heat and electricity High density (heavy for their size) High melting point Ductile (most metals can be drawn out into thin wires) Malleable (most metals can be hammered into thin sheets)

Chemical Properties of Metals: Easily lose electrons (cations) Corrode easily React with acids

Nonmetals Nonmetals are found to the right of the stairstep line. Their characteristics are opposite those of metals.

Physical Properties of Nonmetals: No luster (dull appearance) Poor conductor of heat and electricity Brittle (breaks easily) Not ductile Not malleable Low density Low melting point

Chemical Properties of Nonmetals: Tend to gain electrons (anions)

Metalloids Elements on both sides of the zigzag line have properties of both metals and nonmetals. These elements are called metalloids.

Physical Properties of Metalloids: Solids Can be shiny or dull Ductile Malleable Conduct heat and electricity better than nonmetals but not as well as metals

Alloys A homogeneous mixtures of two or more metals  Also known as a “solid solution”  The mixture is made by melting each metal, combining the metals, and cooling the mixture and to form a solid.  Higher or lower density Rust resistant (aka: oxidation resistant)

Properties of alloys are frequently far different from those of their constituent elements Stronger or weaker

Examples of Alloys: Steel – iron, manganese, and carbon (adding chromium – slows the rusting process, but it makes it more brittle) – used for cars and plane parts, kitchen utensils fixtures, architecture Stainless steel – mixture of iron, nickel, and chromium – Kitchen utensils Gold jewelry – gold, copper, and silver

Sterling silver – silver and a small amount of copper Brass – copper and zinc – used for plumbing, light fixtures, ships Bronze – copper and tin – harder than brass Copper and Nickel Alloy – 90% Cu /10% Ni alloy requires no surface protection and hence gives extra safety, this alloy is being increasingly employed for brake and hydraulic suspension systems and cooling systems in cars and commercial vehicles.

Aluminum alloy - The most common foil alloys - the 1000, 3000 and 8000 series - contain between 0.5% and 1.5% iron, 0.1% and 0.7% silicon and 0.02% to 1.5% manganese. Up to 0.2% copper may be added when additional strength is required

Purpose of Alloys Design of rockets, spacecraft, and aircraft materials need to be light weight, very strong, and able to sustain very high temperatures alloys with aluminum, beryllium, and titanium Prosthetic implants bombarding titanium with nitrogen

Amalgams – mercury with other metals old fashioned way of filling a cavity was with mercury and silver Car parts – rims, brakes, shocks And many others….can you think of any?

Element Research Project

Periodic Table Group or Family Period Vertical column on the periodic table Have similar properties Group A elements have the same charge Group B elements are transition elements Period Horizontal row 7 periods on the periodic table

Dmitri Mendeleev organized the elements based on their properties and increasing atomic mass (1869) Predicted properties for elements that were not discovered yet Ekasilicon for Germanium

Periodic Law the properties of the elements repeat in a regular manner

Henry Mosley reorganized the periodic table based on atomic number (1913)

Properties used to organize the periodic table Atomic Mass – average of the masses of the isotopes that make up the element and their abundance (amu) Density – ratio of mass to volume (g/cm3) Melting Point – temperature at which a solid is in equilibrium with the liquid phase (Kelvin)

Atomic Radius – Distance from the center of an atom’s nucleus to its outermost electron (nanometer nm) Ionization Energy – energy needed to remove one electron (kilojoules per mole kJ/mole); Form a positive charge; Metals like to form cations – low energy

Electronegativity – ability of an atom to attract an electron (no units) Fluorine is the most electronegative atom Electron Affinity – the energy needed to add/gain one electron; Form a negative charge; Nonmetals like to form anions – low energy