Download Periodic Table Vocabulary Periodic Table – a chart that organizes

Periodic Table Vocabulary
Periodic Table – a chart that organizes information about all of the known elements
according to their properties.
Matter – anything that has mass and volume.
Element – a substance that cannot be broken down into a simpler substance by
ordinary chemical means.
Elemental Symbol – the single capital letter or capital letter followed by a lower case
letter or letters that represents the name of the element.
Atom – the smallest unit of an element that has all of the properties of the element;
basic building block of matter.
Molecule – two or more atoms covalently bond in fixed proportion.
Compound two or more different elements bond in fixed proportion
Atomic Mass – the number of protons and neutrons in the nucleus of one atom of the
element. Located under the elemental symbol (at the bottom of the element box on the
periodic table).
Atomic Number – the number of protons contained in each nucleus of its atoms of the
element. Located over the elemental symbol (at the top of the element box on the
periodic table).
Period – a horizontal row (left to right) in the periodic table.
Group – a vertical column (up and down) on the periodic table.
Reactivity – describes how likely an element is to form bonds with other elements.
Valence Electrons – electrons that are located in the outermost principle energy level
of an atom.
Electron Cloud – the region surrounding the nucleus of an atom where the electrons
are located.
Ion – an atom that has gained or lost one or more electrons.
Ionic Bond – a bond formed by the transfer of electrons (when valence electrons of
one atom are transferred to the outer energy level of another atom). (M with non M)
Covalent Bond – a bond formed when two atoms share valence electrons.
(non M with non M)
The Atomic Theory States:
(1)
All matter is composed of atoms
(2)
Atoms of a given element are identical
(3)
Atoms of different elements combine in simple whole-number ratios to form
chemical compounds.
Metal – an element or substance that conducts heat and electricity.
Nonmetal – an element that does not conduct electricity or heat and is usually a gas at
room temperature.
Metalloid – an element that has some properties of a metal and some properties of a
nonmetal.
Inert – elements and/or compounds that when put together are unable to react
chemically.
The Law of Conservation of Matter – a scientific law that states that during a
chemical reaction, matter cannot be created or destroyed but can be changed into a
different form.
Period law- The chemical properties of elements tends to repeat over specific atomic
number intervals
Law of definite proportions – elements within a compound have specific mass ratios
Isotopes Atoms of the same element but with different numbers of neutrons
1st ionization energy The energy required to remove the most loosely held valence
electron from an atom to form a positive ion.
Electronegativity The tendency of an atom to withdraw electron density from a covalent
bond, between it and another atom.
Exothermic A process that gives out energy
Endothermic A process that requires energy