The Periodic Table: A systematic catalog of elements. Elements are arranged in order of atomic number.

Periodicity When one looks at the chemical properties of elements, one notices a repeating pattern of reactivities.

Periodic Table The rows on the periodic chart are periods. Columns are groups or Families. Elements in the same group have similar chemical properties.

Three main types of elements in the periodic table: 1.Metals 2.Nonmetals 3.Metalloids – metal-like elements

Periodic Table Metals are on the left side of the chart (left of the zigzag line).

Physical Properties of Metals: ~ Shiny (some) ~ High density ~ High melting point ~ Conductors – transport heat and electricity ~ Malleable – can be pounded into shapes ~ Ductile – can be pulled out into wires ~ Magnetic – attracted to magnets – Fe, Co, Ni

Chemical Properties of Metals: ~ Some metals very reactive – Na and K ~ Some are very unreactive – Au and Cr ~ Some are in between ~ lose 1, 2, 3, or 4 valence electrons during reactions.

Metals form alloys – a mixture of two or more elements. ~ Cu + Sn = Bronze ~ Cu + Zn = Brass

Groups These five groups are known by their names.

Alkali metals – Group 1 ~ very reactive – ~ Have 1 valence electron Alkaline Earth metals – Group 2 ~ reactive ~ have 2 valence electrons

Transition metals – Group 3-12 ~ Fairly stable, hard, shiny – Ex. Gold, iron, copper, nickel, silver. ~ Have 1, 2, 3, or 4 valence electrons Lanthanides and Actinides – bottom of table ~ rare earth elements.

Periodic Table Nonmetals are on the right of the zigzag line in periodic table (with the exception of H).

Physical properties of Nonmetals– opposite of metals Chemical properties – gain 1, 2, 3, or 4 electrons during reactions.

~ Between metals and nonmetals ~ They border the zigzag line (with the exception of Al and Po). ~ Most common metalloid is silicon

Stars, including the sun, are made mostly of hydrogen. They exist in the state of plasma (atoms are stripped off electrons and nuclei are closely packed). Fast moving protons in nuclei collide and fuse together in nuclear fusion. A huge amount of energy is released in the process.

Nuclear Fusion In the sun, some hydrogen atoms have 1 or 2 neutrons

What Elements can form in the Sun? Happens inside sun The process of combining smaller nuclei to form larger nuclei, thus producing heavier elements.

H + HHe He + He Be Be + HeC C + HeO Oxygen (O) is heaviest element that can form in our sun.

Elements from Large Stars Larger, hotter stars can produce Mg, Si, and even Fe Heavier than Fe elements are produced in a supernova (explosion of massive stars) Our sun, Earth, & other planets were formed as a result of a gigantic supernova billions of years ago. This means, everything on Earth is made of stardust!!!!!!!!!