Vocabulary Word | Definition |
ductile | material that can be pulled out, or drawn, into a long wire |
reactivity | ease of an element to combine or react with other elements and compounds |
malleable | material that can be hammered or rolled into flat sheets and other shapes |
amu | atomic mass units - protons or neutrons have a mass equal to one amu |
chemical symbol | a one or two letter abbreviation of an element's name |
alloy | a reaction of a metal with another element, usually another metal |
covalent bond | atoms held together by sharing electrons |
ionic bond | charged particles held together by an electrical attraction |
valence electrons | electrons found in the outermost or valence shell of an atom |
cloud | the part of an atom that contains electrons |
atomic number | the number of protons in the nucleus of an atom |
proton | particle of nucleus that has a positive charge |
isotope | atoms with the same number or protons but a different number of neutrons |
average atomic mass | the average mass of all the isotopes of an element |
neutron | particle of nucleus that has no charge or is neutral |
period | horizontal row of a periodic table |
group | vertical column of a periodic table also known as a family |
electron | particle of atom that has a negative charge and moves rapidly around the nucleus |
conductive | ability to transfer heat or electricity to another object |
corrosion | the destruction of a metal through reaction with air or water |
metal | element whose properties include: shininess, malleability, ductility and conductivity |
alkali metal | Group 1 metals that react by losing one electrons |
alkaline earth metal | Group 2 metals that react by losing two electrons |
transition metal | Groups 3 - 12 metals |
halogens | Group 17 nonmetals that are very reactive |
nobel gases | group 18 unreactive gases |
chemical reaction | losing, sharing, or gaining electrons in its valence shell |
ion | a charged particle that forms when an atom gains or loses electrons |
metallic bond | charged metal ions are attracted to the electron cloud of a metal |
mass of atoms | mostly located in the nucleus |
volume of atoms | mostly the cloud of electrons |
models | used when something is too big or small, too dangerous, or too fast or slow to observe |
atomic particles | smaller particles called protons, neutrons and electrons |
periodic table | contains the chemical name, chemical symbol, atomic number, and average atomic mass |
Mendeleev | arranged the known elements of his day, in a table by atomic mass, failing to consider isotopes |
molecule | the bonding of two or more atoms |
mass number | sum of protons and neutrons in the nucleus of an atom |
diatomic molecule | two atoms of the same element bonded together |
synthetic element | a man-made element not found in nature |
metalloid | an element that have properties of both metals and nonmetals, also called a semi-conductor |
stable atoms | atoms are stable (happy, happy, happy) when they have eight valance electrons or none after reacting (except hydrogen and helium which need only two in the valance cloud or shell) |