Chem Chapter 3 Vocab

Front 1

states that atoms are the building blocks of all matter

Back 1

atomic theory

Front 2

states that two samples of a given compound are made of the same elements in exactly the same proportions by mass regardless of the sizes or sources of the samples

Back 2

law of definite proportions

Front 3

states that the mass of the reactants in a reaction equals the mass of the products

Back 3

law of conservation of mass

Front 4

states that when two elements combine to form two or more compounds, the mass of one element that combines with a given mass of the other is in the ratio of small whole numbers

Back 4

law of multiple proportions

Front 5

Dalton believed that ____ kinds of atoms made up all matter.

Back 5

few

Front 6

________ revised the early Greek idea of atoms into a scientific theory that could be tested by experiments.

Back 6

Dalton

Front 7

Dalton's theory contained 5 principles:

Back 7

- matter is composed of atoms
- atoms of elements are identical
- atoms of different elements differ
- atoms of different elements combine in simple, whole number ratios to form compounds
- atoms are never created or destroyed

Front 8

Particles that make up atoms are called ________________.

Back 8

subatomic particles

Front 9

J.J. Thomson studied electricity by applying a voltage to two metal plates called __________.

Back 9

electrodes

Front 10

The electrode that has a positive charge is the ______.

Back 10

anode

Front 11

The electrode that has a negative charge is the ________.

Back 11

cathode

Front 12

Cathode rays are the glowing beams of light that occurred during __________'s studies.

Back 12

Thomson

Front 13

Thomson's studies created evidence for the _______.

Back 13

electron

Front 14

An electron is a subatomic particle that has a ________ charge.

Back 14

negative

Front 15

Thomson's _________________ of an atom had negatively charged electrons embedded in a ball of positive charge.

Back 15

plum-pudding model

Front 16

____________________ disproved Thomson's plum pudding model with his gold foil experiment.

Back 16

Ernest Rutherford

Front 17

A beam of small, positively charged particles are called _______________. In Rutherford's experiment, these particles were directed at gold foil.

Back 17

alpha particles

Front 18

Rutherford's believed that only a very concentrated positive charge within the gold atom could _____ the alpha particles like they did in his experiment.

Back 18

repel

Front 19

The ________ is an atom's central region, which is made up of protons and neutrons.

Back 19

nucleus

Front 20

The ________ is positively charged and part of the nucleus, atomic number, determines identity.

Back 20

proton

Front 21

__________________ discovered that when alpha particles hit a sample of beryllium, a beam could go through almost anything that was produced.

Back 21

Irene Joliot-Curie

Front 22

The ________ has no charge and is found in the nucleus.

Back 22

neutron

Front 23

____________ states that the closer two charges are, the greater the force between them.

Back 23

Coulomb's law

Front 24

The ________________ is the number of protons in the nucleus of an atom. This number is the same for all atoms of an element.

Back 24

atomic number

Front 25

Atomic numbers are always _______ numbers.

Back 25

whole

Front 26

For an atom to be neutral, it must have the same number of protons as _________.

Back 26

electrons

Front 27

The ________________ is the sum of the numbers of protons and neutrons of the nucleus of an atom.

Back 27

mass number

Front 28

Atoms can have different numbers of ________.

Back 28

neutrons

Front 29

The atomic number always appears on the ______ left side of the symbol.

Back 29

lower

Front 30

Mass numbers are written ______ the atomic number.

Back 30

above

Front 31

An atom that has the same atomic number but has a different atomic mass is called an __________.

Back 31

isotope

Front 32

The difference in energy between two energy levels is known as the ________ of energy.

Back 32

quantum

Front 33

a region in an atom where there is a high probability of finding electrons

Back 33

orbital

Front 34

orbitals are sometimes called ___________.

Back 34

electron clouds

Front 35

a __________ is the distance between two consecutive peaks or troughs of a wave.

Back 35

wavelength

Front 36

all the frequencies or wavelengths of __________________________

Back 36

electromagnetic radiation

Front 37

the effect that happens when light strikes a metal and electrons are released

Back 37

photoelectric effect

Front 38

the lowest energy state of a quantized system

Back 38

ground state

Front 39

a state in which an atom has more energy than it does at its ground state

Back 39

excited state

Front 40

model that states electrons are located in orbitals is the ___________.

Back 40

quantum model

Front 41

a number that specifies the properties of electrons

Back 41

quantum number

Front 42

the ___________________, symbolized by n, indicates the main energy level occupied by the electron, positive integers. as n increases, the electrons distance from the nucleus and the energy increases.

Back 42

principal quantum.

Front 43

symbolized by l, _________________________________, indicates the shape or type of orbital that corresponds to a particular sub level.

Back 43

angular momentum quantum number

Front 44

symbolized by m, _____________________________________, indicates the numbers and orientation of orbitals around the nucleas

Back 44

magnetic quantum number

Front 45

symbolized by +1/2 or -1/2, indicates the orientation of an electron's magnetic field relative to an outside magnetic field.

Back 45

spin quantum number

Front 46

the principle that states that two particles of a certain class cannot be in the same energy state

Back 46

Pauli exclusion principle

Front 47

the arrangement of electrons in an atom

Back 47

electron configuration

Front 48

states that electrons fill orbitals that have the lowest energy first

Back 48

aufbau principle

Front 49

states that orbitals of the same n and l quantum numbers are each occupied by one electron before any pairing occurs.

Back 49

Hund's rule