Ap Biology Ch.2

Front 1

Anion

Back 1

An ion with a negative charge

Front 2

Atom

Back 2

A unit of matter that consists of a nucleus and a negative electron cloud

Front 3

Atomic Nucleus

Back 3

Nucleus of an atom composed of neutrons and protons

Front 4

Atomic number

Back 4

Number of protons in an atom

Determines the element

Front 5

Atomic weight

Back 5

The average mass of atoms of an element

Front 6

Cation

Back 6

An ion with a positive charge

Front 7

Chemical bond

Back 7

A force (covalent, ionic) by which atoms and ions are bound in a molecule

Front 8

Chemical equilibrium

Back 8

Reaction can occur in both directions

The reactants and products eventually become steady, producing a net change of zero

Front 9

Chemical reaction

Back 9

A transformation of one set of chemical substances into another

Electrons work to break and form chemical bonds

DON'T TAKE PLACE IN NUCLEUS

Front 10

Compound

Back 10

Pure chemical substance with two or more chemical elements which can be simplified and broken down through chemical reactions

Have specific structures with atomic ratios, held together by chemical bonds

molecular compounds held together by covalent bonds, salts held together by ionic bonds, intermetallic compounds held together by metallic bonds, or complexes held together by coordinate covalent bonds

Front 11

Covalent Bond

Back 11

Chemical bond via sharing electrons

Polar: water, unequal e- sharing, weak conductor

Nonpolar:oil, equal e- sharing, not a conductor

Front 12

Dalton

Back 12

Chemical changes related to events at atomic level

Front 13

Double Covalent Bond

Back 13

Two pairs of shared electrons O=O

Front 14

Electron shell

Back 14

Outermost shell of electrons around the nucleus of an atom. Contains valence electrons

Front 15

Electron

Back 15

Negatively charged subatomic particle

Front 16

Electronegativity

Back 16

Ability of an atom to attract electrons to itself

Atomic weight and distance between valence and nucleus determining factors

Front 17

Element

Back 17

Pure chemical substance consisting of a single type of atom with the same atomic numbers

Front 18

Energy Level

Back 18

Maximum number of electrons on each level ___s2

Front 19

Energy

Back 19

Energy is a quantity that can be assigned to any particle, object, or system of objects as a consequence of its physical state

Kinetic, potential, thermal, gravitational, sound, elastic and electromagnetic (often named after related force)

Front 20

Hydrogen Bond

Back 20

Attractive interaction between hydrogen atom (+) and electronegative atom.

Weak bond, but stronger than van der Waals

Front 21

Ion

Back 21

Electrons don't equal protons

Cation= +
Anion= -

Front 22

Ionic Bond

Back 22

Metal and nonmetal ion
(Positive bonded to negative)

Transfer of ions in order to create opposite electrical attractions, thus bringing them together

Front 23

Ionic Compound

Back 23

Multiple ionic bonds create a three-dimensional crystal/lattice with opposite charges attracting each other until there are no ions left

Front 24

Isotope

Back 24

Same element with different numbers of neutrons

Neutrons add weight and hold the nucleus together

Front 25

Mass Number

Back 25

The number of protons plus the number of neutrons

Front 26

Matter

Back 26

Substance of which all physical objects are made

Has mass/occupies volume

Front 27

Molecular Formula

Back 27

Number of atoms of each element in a molecule

Symbol + subscript of number
(H2O)

Front 28

Neutron

Back 28

Neutrally charged subatomic particle
Heavy
Part of nucleus

Front 29

Nonpolar Covalent Bond

Back 29

Oil
Equal sharing of e-
No conductor

Front 30

Potential Energy

Back 30

Stored energy as a result of position

Front 31

Product

Back 31

End result of a chemical equation

Front 32

Proton

Back 32

Positively charged subatomic particle
Heavy
Atomic Number= Number of protons
Part of nucleus

Front 33

Radioactive Isotope

Back 33

Different number of neutrons --> unstable nucleus decays giving off gamma/alpha/beta rays until stable and turns into a different element

Front 34

Reactant

Back 34

The initial substance of a chemical reaction used with other reactants to form a product

Front 35

Salt

Back 35

Salts are ionic compounds, occurring from neutralization reactions between an acid/base

Cations/anions= neutral

Front 36

Structural Formula

Back 36

Structural formulas show every atom (symbol) and every bond (dashes), as well as the unshared electron pairs found in a molecule.

Front 37

Trace Element

Back 37

Very small concentration or amount

Front 38

Valence Electron

Back 38

An electron in the outermost shell of an atom

Determines how the atom will react with others

Front 39

Valence Shell

Back 39

Outermost electron shell

Complete= noble gas

Front 40

Valence

Back 40

The combining capacity of an atom or radical determined by the number of electrons that it will lose, add, or share when it reacts with other atoms

Front 41

van der Waals interactions

Back 41

van der Waals force is the electric intermolecular force that attract neutral molecules to one another, and it is much softer and weaker than other bonds.

Front 42

Molecule

Back 42

At least two atoms in a neutral arrangement made by covalent (strong) bonds

(Polyatomic have charge)