Unit 2: The periodic table

Element Symbol

A one or two lettered symbol for the element name. First letter is always capitalized, and the second letter is always lowercase.

Electrons

Negatively charged particles outside of the nucleus

Nuclear Atom

Three subatomic particles, protons and neutrons are in the nucleus, and electrons are located outside of the nucleus

Proton

Positively charged subatomic particle. Mass of 1 amu, and is located in the nucleus

Neutron

Neutral subatomic particle. Mass of 1 amu, and it is located in the nucleus.

Isotopes

An element that has the same number of protons but different number of neutrons. For example, C-12 and C14

Atomic Number

The number above the symbol on the periodic table. Also, the number of protons in an element.

Atomic Mass

The number below the symbol on the periodic table. The average for all of the different isotopes of that element

Dalton's Atomic Theory

Elements are made of tiny particles called atoms, matter can not be created or destroyed

JJ Thomson's experiment

Used the cathode ray tube, and discovered a negatively charged particle in the atom - the electron

Rutherford's experiment

Used the gold foil experiment, discovered a small dense positively charged nucleus

Law of conservation of matter/mass

Matter/mass can not be created or destroyed, it is conserved

Mass number

The protons and neutrons in an atom

Periodic table

A table used to arrange elements by increasing atomic number.

Groups/Families

Alkali (Group 1A), Alkaline earth metals (2A), Transition metals, Metalloids, Halogens (7A), Noble gas (8A)

Alkali metals

Group 1A metals

Alkaline earth metals

Group 2 A metals

Halogens

Group 7 a nonmetals

Noble gases

Group 8A nonmetals- nonreactive

Transition metals

Metals to the left of the stair case

Metals

Luster, malleable, ductile, and conducts electricity

Nonmetals

Dull, brittle, not ductile, not able to conduct electricity

Metalloids- Semi metals

along the stair case- characteristics of both a metal and a nonmetal

Density

The amount of matter in a given amount of space

Fluorine

The most electronegative element on the periodic table