Chapter 12
Terms
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- Potassium
- K, Kalium
- Henry Moseley
- British scientist, determined the number of protons, atomic number, in an atom
- Dmitri Mendeleev
- Russian chemist, discovered a pattern to the elements, 1869, arranged by increasing atomic mass, made the periodic table
- Period
- a horizontal row of elements in the periodic table
- Alkali metals
- Group 1, 1 electron in outer level, very reactive, soft, silver, shiny, low density; Lithium, Sodium, Potassium, Rubidium, Cesium, Francium
- Copper
- Cu, Cuprum
- Group
- a vertical row of elements in the periodic table, elements in group share chemical properties, also called a family
- Metalloids
- also called semiconductors, about half of a set of electrons in their outer energy levels
- Tin
- Sn, Stannum
- Boron Group
- 3 electrons in the outer energy level, reactive, solids at room temperature; Boron, Aluminum, Gallium, Indium, Thallium
- Lead
- Pb, Plumbum
- Sodium
- Na, Natrium
- Periodic
- describes something that occurs or repeats at regular intervals
- Lanthanides
- in the 1st row of transition metals; shiny, and reactive metals
- Silver
- Ag. Argentum
- Periodic Law
- the law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements
- Iron
- Fe, Ferrum
- Alkali-earth metals
- Group 2, 2 electron in the outer energy level, very reactive but less reactive than alkali metals, silver, higher densities than alkali metals; Beryllium, Magnesium, Calcium, Strontium, Barium, Radium
- Mercury
- Hg, Hydrargyrum
- Gold
- Au, Aurum
- Transition metals
- Groups 3-12, 1-2 electrons in the outer energy level, less reactive than alsali-earth metals, shiny, good conductor of thermal energy and electrical current, high density
- Properties of Nonmetals
- not malleable, not ductile, not shiny, poor conductors of thermal energy and electrical current
- Nonmetals
- almost a complete set of electrons in the outer energy level, more than half are gases at room temperature
- Properties of Metals
- shiny, ductile- can be drawn into thin wires, good conductors of electrical current and thermal energy, and malleable- can be flattened without being smashed
- Actinides
- in the 2nd row of transition metals, radioactive, unstable, do not occur in nature
- Properties of metalloids
- shiny, brittle, hard, good conductors of electrical currents
- Tungsten
- W, Wolfram
- Metals
- few electrons in the outer energy level, most are solid at room temperature
- Antimony
- Sb, Stibnum