sci vocab ch 19
Terms
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- noble gases
- group 18 elements are called _______ ________ because they rarely combine with other elements, and are chemically inactive
- metal
- element with luster and is a good conductor of heat and electricity
- semiconductor
- element that doesn't conduct electricity as well as a metal, but conducts electricity better than a nonmetal
- nonmetals
- usually gases or brittle solids at room temperature that are poor conductors of heat and electricity
- ductile
- this means that they can be drawn into wires
- halogens
- fluorine, chlorine, bromine, iodine, astatine
- malleable
- many metals can be pressed or pounded intothin sheets or shaped into objects because they are malleable
- alkaline earth metals
- active, but not as active as alkali metals
- alkali metals
- silvery solids with low densities and low melting points
- lanthanides
- also called the rare earth elements because they were thought to be scarce
- actinides
- all of these are radioactive and most are synthetic elements
- period
- row of elements in the periodic table whose properties change gradually and predictably
- synthetic elements
- elements that do not occur naturally on earth and are marked with a bullseye logo
- group
- contains elements with similar physical/chemical properties
- alloy
- mixture of two or more elements, one of which is a metal
- luster
- ability to reflect light
- metalloid
- has some propreties of a metal and some properties of nonmetals
- symbols
- the ______ for the elements are either one- or two-letter abbreviations, often based on the element name