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34 terms

Physical Science-- atoms, molecules, and ions

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Atoms
Elements are composed of extremely small particles called? (#1 in Dalton's Atomic Theory)
#2 in Dalton's Atomic Theory
All atoms of a given elemen are identical, having the same size mass and chemical properties. The atoms of one element are different from the atoms of all other elements.
Compounds
______ are composed of atoms of more than one element. In any compound, the ratio of the numbers of atoms of any two of the elements present is either an integer or a simple fraction. (#3 in Dalton's Atomic Theory)
Chemical Reaction
A ______ involves only the seperation, combination, or rearrangement of atoms; it does not result in their creation or destruction. (#4 in Dalton's Atomic Theory)
Neutron
is neutral.
Atoms positive charge is concentrated in
the nucleus.
Proton
Positive
Electron
Negative
mass of p is ___ X the mass of e
1840
Atomic Number
number of protons in nucleus.
Mass Number
number of protons + number of neutrons OR atomic number + number of neutrons
Isotopes
are atoms of the same element with different numbers of neutrons in their nuclei.
The isotopes of hydrogen
same number protons, different numbers of neutrons theefore mass is different.
Natural abundance of elements in earths crust
oxygen 45.5%, silicon 27.2%, all others 5.3%, Magnesium 2.8%, Calcium 4.7%, Iron 6.2%, Aluminum 8.3%
Natural abundance of elemets in human body
Oxygen 65%, Carbon 18%, Al others 1.2%, Phosphorus 1.2%, Calcium 1.6%, Nitrogen 3%, Hydrogen 10%
Mendeleev
created the first periodic table. based on increasing atomic mass.
Moseley
Modern Periodic Table. Currently used table, based on increasing atomic number.
Molecule
an aggregate f wo or more atoms in a definite arrangement held together by chemical forces.
Diatomic Molecule
contains only two atoms.
Polyatomic Molecule
contains more than two atoms.
Ion
an atom, or goup of atoms,that has a net positive or negative charge.
Cation
ion with a positive charge. If a neutral atomloses one or more electrons it becomes a cation.
Anion
ion with a negative charge. If a neutral atom gains on ore more electrons it becomes an anion.
Monatomic ion
contains only one atom.
Polyatomic ion
contains more than one atom.
Molecular formula
shows the exact number of atoms of each element in the smallest unit of a substance.
Emirical formula
shows the simplest whole-number ratio of the atoms in a substance.
Ionic compounds
consists of a combination of cations and an anions.
Transition metal ionic compounds
indicate charge on metal with roman numerals
Acid
can be defined as a substance that yields hydrogen ions when dissolved in water.
Base
can be defined as a substance that yields hydroxide ions when dissolved in water.
Hydrates
compounds that have a specific number of water molecules attached to them.
Organic Chemistry
the branch of chemistry that deals with carbon compounds.
Precipitate
insoluale solid seperates from solution.