A way of organizing & classifying elements Arranged in rows and columns
Columns The vertical (up and down) columns of the periodic table (there are 18) are called groups or families. Elements in the same group or family have similar characteristics or properties.
Rows The horizontal rows of the periodic table are called periods. Elements in a period are not alike in properties. The first element in a period is usually an active solid, and the last element in a period is always an inactive gas.
Rows Atomic size (number of protons) decreases from left to right across a period. Atomic mass (number of protons) increases from left to right across a period.
Rows Metals are on the left Non-metals are on the right
very reactive metals that do not occur freely in nature malleable, ductile, good conductors of heat and electricity. softer than most other metals can explode if they are exposed to water ALKALI METALS
metals very reactive not found free in nature ALKLINE EARTH METALS
ductile and malleable, and conduct electricity and heat iron, cobalt, and nickel, are the only elements known to produce a magnetic field. TRANSITION METALS
OTHER METALS are ductile and malleable are solid, have a relatively high density, and are opaque
METALLOIDS have properties of both metals and non- metals some of the metalloids, such as silicon and germanium, are semi-conductors. This means that they can carry an electrical charge under special conditions. This property makes metalloids useful in computers and calculators
NON-METALS not able to conduct electricity or heat very well very brittle, and cannot be rolled into wires or pounded into sheets exist in two of the three states of matter at room temperature: gases (such as oxygen) and solids (such as carbon). have no metallic luster, and do not reflect light.
HALOGENS "halogen" means "salt-former" and compounds containing halogens are called "salts" exist in all three states of matter: Solid- Iodine, Astatine Liquid- Bromine Gas- Fluorine, Chlorine