Download Vocabulary for Periodic Table

Vocabulary for Periodic Table (Chapter 5)
1) Proton: a positively charged particle located in an atom’s nucleus.
2) Neutron: a particle that has no electric charge and is located in an atom’s nucleus.
3) Nucleus: the central region of an atom where most of the atom’s mass is found in
protons and neutrons.
4) Electron: a negatively charged particle located outside an atom’s nucleus.
5) Atomic number: the number of protons in the nucleus of an atom.
6) Atomic mass number: the total number of protons and neutrons in an atom’s
nucleus.
7) Isotope: atoms of the same element that have a different number of neutrons.
8) Ion: when an atom loses or gains electrons.
9) Atomic mass: the average mass of the atoms in an element.
10) Periodic Table: a table of elements, arranged by atomic number, that shows the
patterns in their properties.
11) Group: a vertical column in the periodic table of the elements that have similar
properties; also called a family.
12) Period: a horizontal row in the periodic table of elements that have varying
properties.
13) Reactive: indicates how likely an element is to undergo a chemical change.
14) Metal: an element that tends to be shiny, easily shaped, and a good conductor of
electricity and heat.
15) Nonmetal: an element that is not metal and has properties generally opposite to
those of metal.
16) Metalloid: an element that has properties of both metal and nonmetal.
17) Radioactivity: the process by which the nucleus of an atom of an element
releases energy and particles.
18) Half-life: the amount of time it takes for one-half of the atoms in a particular
sample to decay.