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 What are the parts of an atom?  Nucleus – The center of the atom. It contains…  Protons – Positively charged particles.  Neutrons – that have no charge.  Outside the nucleus…  Electrons – Negatively charged particles.  Every atom of the same element has the same number of protons.

 What is the Periodic Table?  It’s an arrangement of elements showing the repeating pattern of properties.  Created by Mendeleev  He grouped them according to chemical and physical properties.

 How do you read the Periodic Table?  For each element it tells the Atomic Number, the Atomic Mass, The Chemical Symbol, and the Chemical Name.  The Atomic Number tells the number of protons (and usually the number of electrons)  Atoms with a different number of electrons than protons are called ions and are electrically charged particles.

 What is Atomic Mass?  It is the average mass of all the isotopes of that element.  (Remember, an Isotope is an element that has the same amount of protons but a different amount of neutrons changing it’s mass.)

 How is the Periodic Table Useful?  An element’s properties can be predicted from looking at its location in the Periodic Table.  Atomic Numbers are in order from left to right, and similar properties are grouped together in columns.

 What is a period?  A row on the Periodic Table.  Properties change in a predictable way as you go from left to right.  Metals are shown on the left and nonmetals on the right with metalloids in the middle.

 What is a Group?  The elements in a column form a group.  Each group is known as a family.  The Elements in each group have similar characteristics.  For example – all elements in group 1 (except for hydrogen) are metals that react violently with water.

 How are elements grouped together?  The elements are grouped together in three main categories:  Metals  Nonmetals  Metalloids

 What are the properties of metals?  Physical:  High luster – shiny and reflective  Malleable – can be hammered into flat sheet  Ductile – can be pulled out or drawn into a wire  Thermal conductivity – can transfer heat  Electrical conductivity – can transfer electricity

 Properties of metals cont…  Chemical:  Reactivity – the ease or speed that elements react or combine with other elements. Most metals react by losing electrons to other atoms.  Corrosion – the gradual deterioration of a metal due to a chemical reaction with the environment.

 How are metals classified?  Metals are classified into 6 categories:  Alkali metals  Alkaline earth metals  Transition metals  Metals in mixed groups  Lanthanides  Actinides

 What are Alkali Metals?  They are VERY REACTIVE!!!!!  The metals in group 1 from lithium (li) to francium (Fr)  They are never found by themselves in nature – always in a compound.  They are shiny and very soft – some can be cut with a plastic knife!  They have low densities and low melting points – ex. Sodium melts at 98 C and is less dense than water!

 Alkaline Earth Metals  Reactive – but not as reactive as the alkali metal group.  They are more dense and melt at higher temperatures – ex. Magnesium (Mg) melts at C.  Calcium is one of the most common alkaline earth metals – needed for healthy bones.

 Transition metals  Most are hard and shiny solids (except for Mercury which is a liquid at room temp.)  Includes iron, copper, nickel, gold and silver.  High melting points and high densities.  Good conductors  Very malleable  Less reactive than 1-2

 Metals in mixed groups  Only some of elements in groups 13 – 16 are metals.  Include Aluminum, Tin, Lead.  Not very reactive – used to coat other metals so they won’t corrode.

 Lanthanides and Actinides  Many of these elements are synthetic (not naturally found but artificially made in laboratories).  They are made using particle accelerators.

 Transuranium Elements  The synthesized elements found on the table past Uranium. They are made by crashing the nuclei of atoms together at extremely high speeds using particle accelerators.

 What are the properties of Nonmetals?  Physical:  Dull  Brittle  Poor conductors of both heat and electricity.

 Nonmetals cont….  Chemical Properties:  Atoms of nonmetals usually gain or share electrons with other atoms. Electrons move from metals to nonmetals. Sometimes nonmetals join together to form compounds such as H2O

 Families containing Nonmetals  The Carbon Family  The Nitrogen Family  The oxygen Family  The Halogen Family  The Noble Gases  Hydrogen

 The Carbon family  Group 14  Most fuels used to yield energy contain carbon such as coal, gasoline, crude oil.  Carbon is important to life – proteins, carbs, DNA, fats.  Diamonds are pure carbon.

 Nitrogen family  Oxygen family  Group 15  Contains 2 nonmetals – Nitrogen and Phosphorous.  Group 16  Contains 3 nonmetals – Oxygen, Sulfur, and Selenium. O – gas  S & Se - solids

 Halogen family  Group 17  Nonmetals include Florine, Chlorine, Bromine and Iodine.  Halogen means “salt forming”  Although halogen elements are dangerous – they are useful – water treatment, toothpaste.

 The Noble Gases  Group 18  Usually nonreactive.  Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe).  Used in Balloons and Neon lights.

 Hydrogen  Alone in the upper left corner of the Periodic table.  Properties very different than all others, so it is not grouped with a family.  Hydrogen makes up more than 90% of all atoms in the universe, but only 1% on Earth.

 What are Metalloids?  They have some properties of metals and some of nonmetals.  Solids  Brittle, hard, somewhat reactive.  Semiconductors (conduct electricity under certain conditions)

 Models 0f atoms….  Notes…..