Dmitri Mendeleev arranged the known elements by characteristics. He summarized his findings in the periodic law which states: When the elements are arranged in order of increasing mass, certain sets of properties recur periodically. The elements are arranged in increasing order according to atomic mass. They are arranged in rows and columns based on characteristics of elements.

Broadly elements can be divided into 3 groups Metals: good conductors of heat and electricity, they are malleable (can be pounded into flat sheets), they are ductile (can be drawn out into thin wires), shiny, lose electrons, chemically reactive. Examples include chromium, copper, strontium, and lead

Nonmetals: can be solids, liquids, or gases, poor conductors of heat and electricity, gain electrons, undergo chemical changes. Examples include oxygen, carbon, sulfur, and bromine

Metalloids: show mixed properties between metals and nonmetals. They are called semiconductors with intermediate conductivity. Examples include silicon, arsenic, and antimony

The Metal, Metalloids, and Nonmetals are arranged in particular portions of the Periodic Table.

Each column of the Main group elements is called a family or group. Each group has specific characteristics Noble gases- Group 8A Not reactive in most chemical reactions, they are considered stable with no charge.

Alkali Metals- Group 1A are all reactive metals, Some are explosive. Have a positive 1 charge.

Alkaline earth metals- Group 2A- Also fairly reactive, but not as reactive as the alkali metals. Have a 2+ charge. DkAye4=&h=600&w=724&sz=34&hl=en&start=5&itbs=1&tbnid=CQBSvcszpC81oM:&tbnh=116&tbnw=140&prev=/images%3Fq%3DAlkaline%2Bearth%2Bmetals%26hl%3Den%26 gbv%3D2%26tbs%3Disch:1

Halogens- Group 7A Very reactive nonmetals. Have a negative 1 charge as ions.

The transition metals are in the middle of the table and have varying charges