science 4 Periodic Flash Cards
Periodic Table
An arrangement of elements in columns based on a set of properties that repeat from row to row.
Mendeleev
A chemist who developed the periodic table and organized elements by their properties while leaving empty spaces for more elements to be discovered.
Element
A pure substance that cannot be broken down.
Period
A row going across on the Periodic Table.
Group
A column going up and down on the Periodic Table.
Periodic Law
The pattern of repeating properties down each group in the periodic table.
Chemical Element Symbol
A one or two letter symbol that represents that name of an element
first letter is capital and potential second letter is lowercase.
Atomic Number
number of protons in an element,
atomic is also equal to the number of electrons.
Atomic Mass
The number of protons and neutrons in the nucleus center of an element.
Conductor
A material that allows things to flow
Metal
elements that are good conductors of heat and electric current
Nonmetal
elements that are poor conductors of heat and electric current
Metalloid
elements with properties that fall between those of metals and nonmetals
Noble Gas
Elements in group 18, stable and unreactive
proton
A particle with a positive charge, same amount as atomic number, this particle identifies the element
Electron
A particle with a neutral charge, same amount as (atomic mass - atomic number)
Valence Electron
Electrons on the outermost shell
Orbital / Shell / Energy Level
Outer boundary of an atom, mostly empty space, each shell starting from the first shell can hold:
1st shell - 2 electrons
2nd shell - 8 electrons
3rd shell - 18 electrons
4th shell - 32 electrons
Nucleus (in an atom
the center of an atom that contains neutrons and protons and therefore most of the mass
Chemical Bond
a force of attraction between atoms to make them more stable
Ion
when atoms transfer electrons and become charged particles
Ionic Bond
the force of attraction that holds together positive and negative ions, a transfer of electrons
Covalent Bond
A force of attraction that holds together two atoms and shares electrons
Chemical Formula
shows the elements involved in that molecule and the number of atoms of each element