Periodic Table (The Periodic Table)

Group 1

Alkali metals.

Group 2

Alkaline earth metals

Groups 3-12

transition metals

metalloids

Found along the 'staircase'. Have properties of both metals and nonmetals

nonmetals

brittle , dull, poor conductors of heat and electricity

Proton

Positively charged particle in the nucleus of an atom (similar mass to neutron)

Neutron

A subatomic particle that is neutral and found in the nucleus of an atom (similar mass to proton)

Electron

A tiny, negatively charged particle that moves around the nucleus of an atom.

Atomic Number

The number of protons in the nucleus of an atom of an element

Mass Number

The total number of protons and neutrons in an atom's nucleus

Periodic table

A chart of all chemical elements currently known, organized by their properties.

Element

pure substance that consists entirely of one type of atom

atom

the smallest unit of an element that maintains the properties of that element

periods

horizontal rows on the periodic table

groups

vertical columns on the periodic table that have common properties

metal

shiny, malleable, ductile and good conductors

conductivity

the ability of an object to transfer heat or electricity to another object

reactivity

the ease and speed with which an element combines or reacts with other elements and compounds

alkali metals

very reactive, not found alone in nature, react violently with water

alkaline earth metals

hard, grey-white, good conductors of electricity, calcium and magnesium are examples

Transition metals

most are hard and shiny, less reactive, examples are iron, copper, nickel and gold

synthetic elements

not found naturally on earth, all elements higher than 92

Bohr

discovered that electrons follow an orbit/shell

Dalton

discovered that atoms of the same element have the same mass

Covalent bond

the sharing of electrons

Ionic bond

the transfer of electrons

Ion

forms when an atom loses or gains an electron

Isotope

the protons remain the same as the atomic number, but the neutrons do not

Noble gases

elements in group 18 that have complete outer shells

Halogen

group 17

Valence electrons

electrons that are located the farthest away from the nucleus- determine bonding

Radioactive isotopes

are unstable

Period number

is the amount of energy levels (shells) an atom has

atomic mass

weighted avg of all naturally occurring isotopes of that element; number on periodic table below chemical symbol