Simplest Matter Elements Elements Element Matter made of

Simplest Matter Elements

Elements • Element- Matter made of only one kind of atom. – 112 known elements (92 naturally occur on Earth) • 20 synthetic elements (made by scientists)

Periodic Table • Chart used to organize and display the elements • International system understood by scientists everywhere.

Periodic Table • Elements organized on periodic table by their properties – Rows are called periods • Elements in a row have same number of energy levels – Columns are called groups • Elements in a column have similar properties related to their structure also form similar bonds • (Same Valence Electrons!!!!!!!)

Identifying Characteristics • Each element is different and has unique properties • Atomic Number- Tells you the number of protons in the nucleus of each atom of that element. • Mass Number- Number of protons plus the number of neutrons it contains. • Atomic Mass- Weighted average mass of the isotope of an element. • Isotope- Atoms of the same element that have different number of neutrons.

Classification of Elements • 3 general categories: Metals, nonmetals, and metalloids • Metals- Generally have a shiny or metallic luster and are good conductors of heat and electricity – All solid at room temperature except mercury – Malleable (bent or pounded into various shapes) – Ductile (drawn into wires without breaking)

Classification of Elements • Nonmetals- Usually appear dull in appearance and are poor conductors of heat and electricity. – Many are gasses at room temperature – 97% of body is made up of various nonmetals

Classification of Elements • Metalloid- Elements that have characteristics of metals and nonmetals – Solid at room temperature

Where Do Elements Come From? • http: //www. youtube. com/watch? v=z. UDDi Wt. Ft. EM