Atoms and ions Flashcards
Atom
The basic particle from which all elements are made is the smaller particle of an element that has properties of that element.
Electron
A tiny, negatively charged particle that moves around the outside of the nucleus of an atom
Nucleus
The central core of an atom, which contains protons and neutrons
Proton
A small, positively charged particle that is found in the nucleus of and atom
Neutron
a small particle in the nucleus, with no electrical charge
Atomic number
the number of protons in the nucleus of an atom
Isotope
An atom with the same number of protons and a different number of neutrons form other atoms of the same element
Mass number
The sum of protons and neutrons in the nucleus of an atom
Democritus
in 400 B.C.E. he theorized that all material bodies are made up of extremely small “atomos”
John Dalton
In 1803 he said that all matter was comprised of invisible and indestructible atoms with distinct masses and properties.
J.J. Thomson
In 1897, he discovered negatively charged particles called electrons, he stated that electrons must be stuck all throughout a positively charged area
Ernest Rutherford
He discovered that an atom is mostly empty space, and nearly all of its mass is concentrated in the central nucleus.
James Chadwick
He discover uncharged particles and called them neutrons.
Nelis Bohr
He discovered the electrons are arranged in energy levels.
Atomic mass
The average mass of all the isotopes of an element
Periodic table
An arrangement of elements showing the repeating pattern of their properties
Chemical symbol
A one or two-letter abbreviation foe an element
Period
A horizontal row if elements in the periodic table
Group
Elements in the same vertical column of the periodic table: also known as a family
Compound
A substance made of two or more elements chemically combined in a specific ratio or proportion
Valence electrons
The electrons that are in the highest energy level of an atom and that are involved in chemical bonding
Reactivity
The ease and speed with witch an element combines , or reacts with other elements or compounds
Malleable
A term used to describe material that can be hammered or rolled into flat sheets
ductile
A term used to describe a material that can be pulled out into a long wire.
Luster
The way a mineral reflects light form its surface
Semiconductor
a substance that can conduct an electric current under some conditions.
Ion
An atom or group of atoms that has become electrically charged
polyatomic ion
An atom that is made of more that one atom
Ionic bond
The attraction between ions with opposite charges
Covalent bond
A chemical bond formed when two atoms share electrons
Molecule
A neutral group of two of more atoms held together by covalent bonds
Nonpolar bonds
A covalent bond in which electrons are shared equally
polar bond
A covalent bond in which electrons are shared unequally
Alkali metals
group 1
Alkali earth metals
group 2
Transition metals
groups 3-12
halogen metals
group 17
noble gases
exhibit great stability and extremely low reaction rates, group 18
nonmetals
a chemical element that generally lacks a predominance of metallic properties
Metaloid
a chemical element that forms a simple substance having properties intermediate between those of a typical metal and a typical nonmetal
how many elements are on the periodic table
118
Maximum electrons in a shell pattern
2,8,8,18,18, 32
