Chemistry, Chapter 3

Front 1

Chemical reaction

Back 1

The transformation of a substance or substances into one or more new substances

Front 2

Law of conservation of mass

Back 2

Mass is neither created nor destroyed during ordinary chemical reactions or physical changes.

Front 3

Law of definite proportions

Back 3

A chemical contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound

Front 4

Law of multiple properties

Back 4

If two or more different compounds are composed of the same two, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers

Front 5

Daltons atomic theory

Back 5

1- All matter is composed or extremely small particles called atoms
2- Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass and other properties
3- Atoms cannot be subdivided, created, or destroyed
4- Atoms of different element combine in simple whole-number ratios to form chemical compounds
5-In chemical reactions, atoms are combined, seperated, or rearranged

Front 6

Scientific theory

Back 6

theory that can be tested by experiments

Front 7

Modern atomic theory

Back 7

1-All matter is composed of atoms
2-Atoms of any one element differ in properties from atoms of another element remain unchanged.

Front 8

Atom

Back 8

the smallest particle of an element that still retains the chemical properties of that element

Front 9

nucleus

Back 9

the very small region located at the center of the atom

Front 10

Proton

Back 10

Positively charged particle located in the nucleus

Front 11

neutrons

Back 11

Neutrally charged particle located in the nucleus

Front 12

Electrons

Back 12

Negatively charged particles which surround the nucleus

Front 13

Subatomic particals

Back 13

-Protons
-neutrons
-electrons

Front 14

cathode ray tubes

Back 14

Glass tubes which carried out experiments

Front 15

nuclear forces

Back 15

These short-range proton-neutron,proton-proton, and nuetron-neutron forces hold the nuclear particles together

Front 16

Atomic number

Back 16

The...of an element is the number of protons of each atom of that element

Front 17

Isotopes

Back 17

Atoms of the same element that have different masses

Front 18

Hydrogen isotopes

Back 18

-protium
-deuterium
-tritium

Front 19

Mass number

Back 19

The .... is the total number of protons and neutrons that make up the nucleus of an isotope.

Front 20

Nuclide

Back 20

....general term for a specific isotope of an element

Front 21

Atomic mass unit (amu)

Back 21

1 amu is exactly 1/12 the mass of a carbon-12 atom

Front 22

Average atomic mass

Back 22

The weighted average of the atomic masses of the naturally occuring isotopes of an element

Front 23

Mole (mol)

Back 23

The amount of a substance that contains as many particles as there are atoms in exactly 12 grams of carbon-12

Front 24

Avogadro's number

Back 24

6.022x10^23- the number if particles in exactly one mole of a pure substance

Front 25

molar mass

Back 25

The mass of one mole of a pure substance

Front 26

Mass to Moles (conversion)

Back 26

1 mol/molar mass of element

Front 27

Moles to mass (conversion)

Back 27

Molar mass of element/ 1 mol

Front 28

Moles to atoms (conversion)

Back 28

6.022x 10^23 atoms/1 mol

Front 29

Atoms to moles (conversions)

Back 29

1 mol/ 6.022 x 10^23