1.6, 1.7, 1.8, 1.9
compound
- can be broken down into elements and has a fixed composition - a pure substance made up of two or more different elements in a fixed, characteristic chemical combination
mixture
- can be seperated into two or more components and has a variable composition of elements, compounds, or both
element
- cannot be broken-down into simpler substances, although different forms of an element are possible - one of the 100 or so pure substances in our world from which compounds are formed
coefficients
A small whole number that appears in front of a formula in a balanced chemical equation
Lothar Meyer
German chemist, also developed a periodic table at the same time as Mendeleev.
2006
When did Pluto lose its status as a planet
diatomic molecule
a molecule consisting of 2 atoms
subatomic particle
a particle that is less complex than an atom
chemical reactions
a process whereby substances described as reactants are transformed into different substances called products.
chemical equation
a representations of a chemical reaction using chemical formulas.
chemical formula
a symbolic way to represent the elementary composition of a substance
periodic table
an orderly arrangement of all the elements based on similarities in their properties
Plutonium
can fuel both nuclear reactors and nuclear bombs.
hydrocarbons
compounds made up only of the elements hydrogen and carbon
William Roentgen
discovered x-rays and received the first nobel prize in physics
metals
elements that are shiny and conduct electricity and heat well
nonmetals
elements that do not conduct heat or electricity well and have no one characteristic appearance
metalloids
elements that lie between metals and nonmetals on the periodic table and do not fall cleanly into either category.
law of conservation of matter and mass
in a chemical reaction, matter and mass are conserved. The mass of the reactants consumed equals the mass of the products formed.
subscripts
numbers written below the line that tell how many atoms of a given type are in a compound.
noble gas
one of the inert elements in Group 8A that undergoes few, if any chemical reactions
halogen
one of the reactive nonmetals in Group 7A, such as fluorine, chlorine, bromine, or iodine
chemical symbols
one- or two letter abbreviations for the elements. (atomic symbols)
groups
organize elements according to important properties that they have in common and are numbered from left to right.
valence shell
outermost electron shell
Nanotechnology
refers to the creation of the materials at the atomic and molecular (nanometer) scale
combustion
the chemical process of burning; that is, the rapid combination of fuel with oxygen to release energy in the form of heat and light
atoms
the smallest unit of an element that can exist as a stable, in pendent entity
molecule
two or more atoms held together by chemical bonds in a certain spatial arrangement