Unit 1 The Chemistry Of Life

Front 1

Matter

Back 1

Anything that takes up space and has mass

Front 2

Element

Back 2

Substance that cannot be broken down to other substances by chemical reactions

Front 3

Compound

Back 3

Substance consisting of two or more elements combined in a fixed ratio

Front 4

Trace Elements

Back 4

Those required by an organism in only minute quantities

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Atom

Back 5

smallest unit of matter that still retains the properties ot an element

Front 6

John Dalton

Back 6

British scientist who helped develop atomis theory around 1800. The atomic theory measures the mass of atoms and subatomic particles

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Atomic Number

Back 7

Number of protons found in the nuclei of an element

Front 8

Mass Number

Back 8

The sum of protons plus netrons in the nucleus of an atom

Front 9

Atomic Weight

Back 9

The approximation of the total mass of an atom

Front 10

Isotopes

Back 10

One of several atomic forms of an element each containing a diffrent number of neutrons and thus giving a diffrent atomic mass

Front 11

Radioactive Isotope

Back 11

An isotope that is unstable, the nucleus decays spontaniously, giving of detectable particles and energy

Front 12

Energy

Back 12

The capacity to do work

Front 13

Potencial Energy

Back 13

The energy stored by matter as a result of its location or spatial arrangement

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Energy Levels

Back 14

The diffrent states of potential energy for electrons in an atom

Front 15

Electron Shells

Back 15

An evergy level representing the distance of an electron from the nucleus of an atom

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Valence Electron

Back 16

Electrons in the outer most electron shell

Front 17

Valence Shell

Back 17

The outermost energy of an atom containing the valence electrons involved in the chemical reactions of that atom

Front 18

Chemical Bonds

Back 18

An attraction between two atoms resulting from a sharing of outer-shell electrons or the presence of opposite chrges on the atoms the bonded atoms gain complete outer electron shells

Front 19

Covalent Bonds

Back 19

A type of strong chemical bond in which two atoms share one pair of valence electrons

Front 20

Molecule

Back 20

Two or more atoms held together by covalent bonds

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Structural Formula

Back 21

A type of molecularnotation in which the constituent atoms are joined by lines representing covalent bonds

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Molecular Formula

Back 22

A type of molecular notation indicating only the quantity of the contituent atons

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Double Covalent Bond

Back 23

A type of covalent bond in which two atoms share two pairs of electrons smbolized by a pair of lines between the bonded atoms

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Valence

Back 24

The bonding capacity of an atom generally equal to the number of unpaired electrons in the atom's outermost shell

Front 25

Electronegativity

Back 25

The attraction of an atom for the electrons of a covalent bond

Front 26

Nonpolar covalent bonds

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A type of covalent bond in which electrons are shared equally between two atsoms of similar electronegativity

Front 27

Polar covalent bonds

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A type of covalent bond between atoms that differ in electronegativity The shared electrons are pulles closer to the more electronegative atom making it slightly negative and the other atom slightly positive

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Ion

Back 28

An atom that has gained or lost electrons thus acquiring a charge

Front 29

Cation

Back 29

An ion with a positive charge produced by the loss of one or more electrons

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Anion

Back 30

A negitively charged ion

Front 31

Ionic Bonds

Back 31

A chemical bond resulting from the attraction between oppositly charged ions

Front 32

Ionic compounds

Back 32

Compounds resulting from the formation of ionic bonds,also known as salt

Front 33

Hydrogen Bonds

Back 33

A type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule

Front 34

Chemical reactions

Back 34

A process leading to chemical changes in matter, involves the makind and/or breaking of chemical bonds

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reactants

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The starting material in a chemical reactions

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Products

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An ending material in a chemical reation

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Chemical equalibrium

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In a reversible chemical reaction the point at whthe rate of the forward reaction equals the rate of the reverse reaction