Chemistry unit 3 concepts and vocab

Chemical reaction

Chemical reaction

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

Law of Conservation of Mass

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

Law of Definite Proportions

The fact that a chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound

Law of Multiple Proportions

If two or more different compounds are composed of the same elements, 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

Dalton's Atomic Theory Rule 1

All matter is composed of extremely small particles called atoms

Dalton's Atomic Theory Rule 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

Dalton's Atomic Theory Rule 3

Atoms cannot be subdivided, created, or destroyed

Dalton's Atomic Theory Rule 4

Atoms of different elements combine in simple whole number ratios to form compounds

Dalton's Atomic Theory Rule 5

In chemical reactions, atoms are combined, separated, or rearranged

Atom

Smallest particle of an element that retains the chemical properties of that element

Nucleus

a very small region located at the center of the atom; and is made up of a proton and neutrons

Electrons

Surrounds the nucleus is a region occupied by negatively charged particles -1

Neutron

A subatomic particle that has no charge and that is found in the nucleus of an atom (0)

Proton

A subatomic particle that has a positive charge and that is found in the nucleus of an atom +1

Mass of Electron

9.109x10^31

Mass of Proton

1.673x10^-27

Mass of Neutron

1.675x10^-27

Nuclear forces

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

Atomic number

Number of protons of each atom of that element

protium, deuterium, tritium

3 types of hydrogen atoms

Protium

Nucleus of this atom consists of one proton and one electron moving about it

Deuterium

Each of this type of atom consists of a nucleus with one proton and one neutron

Tritium

Consists of one proton, two neutrons, and one electron

Isotopes

Atoms of the same element that have different masses

Mass number

Total number of protons and neutrons that make up the nucleus of an isotope

1/12 the mass of a carbon-12 atom

1 amu =

About 1 amu

Hydrogen 1 atomic mass

Average atomic mass

Weighted average of the atomic masses of the naturally occurring isotopes of that element

Mole

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

Avogadro's number

6.022x10^23

Molar mass

the mass of one mole of a pure substance

Plank's constant

6.026x10^-34

Atomic mass= protons+neutrons

Atomic mass formula