Introduction to the Periodic Table

I am Dmitri Mendeleev! I made the PERIODIC TABLE !

Periodic Table -History Dmitri Mendeleev (1871) 1st modern periodic table arranged elements by atomic mass number predicted the presence missing elements elements of similar properties were stacked on top of each other

Periodic Table -History Henry Moseley (1911) Discovered atomic number arrange by atomic number Corrected error with properties of the elements Tellurium atomic number 52 and Iodine atomic number 53.

Periodic Table Periodic - things that have a regular repeating pattern Periodic Table of Elements - an arrangement of elements in order of their atomic number so that elements with similar properties fall in the same column

Periodic Table Zig - Zag Line - Thick bold line that separates metals from nonmetals.

What is the PERIODIC TABLE? o Shows all known elements in the universe. o Organizes the elements by chemical properties.

But what is an element? An element is matter that is made entirely from one type of atom.

But what is matter? Matter is anything that takes up space and has mass.

Main Components of the Atom Proton p + Electron e - Neutron n 0 (Nucleus- p + and n 0 )

Atomic Terminology Atomic Number - # of protons in the atom Atomic Weight – equals the # of protons and the # of neutrons Isotopes – atoms with the same # of protons, but a different # of neutrons

Electron Shells –layers or orbits surrounding the nucleus where electrons exist 1 st shell has two electrons, 2 nd and 3 rd shell has eight, larger numbers of electrons fill the outer shells Atoms/elements are more stable if their outer shell is full.

How do you read the PERIODIC TABLE?

What is the ATOMIC NUMBER? o The number of protons found in the nucleus of an atom Or o The number of electrons surrounding the nucleus of an atom.

What is the SYMBOL? o An abbreviation of the element name.

What is the ATOMIC WEIGHT? o The average number of protons and neutrons in the nucleus of an atom.

How do I find the number of protons, electrons, and neutrons in an element using the periodic table? o # of PROTONS = ATOMIC NUMBER o # of ELECTRONS = ATOMIC NUMBER o # of NEUTRONS = ATOMIC _ ATOMIC WEIGHT NUMBER

Now you are almost as smart as I am! But not as handsome! Man, I look GOOD!

Elements, Compounds, and Mixtures

What is an ELEMENT? o A substance composed of a single kind of atom. o Cannot be broken down into another substance by chemical or physical means.

What is a COMPOUND? o A substance in which two or more different elements are CHEMICALLY bonded together.

What is a MIXTURE? o Two or more substances that are mixed together but are NOT chemically bonded.

Element, Compound or Mixture?

How are elements arranged on the Periodic Table? 1 st, by atomic number, small at the top, large at the bottom 2 nd, by the number of electrons in the outer shell of the atom, arranged in vertically columns called groups 3 rd, by the number of electron shells in the atom, arranged in horizontal rows called periods

The group 2 atoms all have 2 electrons in their outer shells Be (Beryllium) Atom Mg (Magnesium) Atom

The period 4 atoms each have 4 electron containing shells K (Potassium) Atom Fe (Iron) Atom Kr (Krypton) Atom 4 th Shell

Alkali Metals Soft, silvery colored metals Very reactive!!! edu/webdata/U sers/DMcDowel l/GenChem/alka lishow.html

Alkali Metals reacting with water: Li (Lithium) Na (Sodium) K (Potassium) Rb (Rubidium) Cs (Cesium) What would you expect from Francium?!?!

Alkaline Earth Metals Silvery-White Metals Fairly reactive Many are found in rocks in the earth’s crust

Transition Metals Malleable (easily bent/hammered into wires or sheets) Most are good Conductors of electricity

How many things can you think of that have Transition Metals in them?

Metalloids lie on left side of these “zig-zag line” They share properties with both metals and non-metals Si (Silicon) and Ge (Germanium) are very important “semi-conductors”

What are semiconductors used in?

Nonmetals Brittle Do not conduct electricity

Most are Poisonous Fairly reactive Halogens

Chlorine Gas was used as a chemical weapon during World War I. It was used by the Nazis in World War II.

Unreactive Gases at room temperature Noble Gases

Jellyfish lamps made with noble gases artist- Eric EhlenbergerEric Ehlenberger

Colors Noble Gases produce in lamp tubes: Ne (Neon): orange-red Hg (Mercury): light blue Ar (Argon): pale lavender He (Helium): pale peach Kr (Krypton): pale silver Xe (Xenon): pale, deep blue

Lanthanide Series Actinide Series

The lanthanide series is a group of transition elements that have chemical properties similar to lanthanum. Lanthanide metals are also referred to as rare-earth metals. All the members of this series are silvery-white with a metallic lustre, and like all other metals, are malleable and ductile. These elements all have unfilled inner 4f electron orbitals.

The actinide series consists of 14 radioactive elements, most of which have been synthetically produced by chemists in the laboratory. The elements in this series all have chemical properties similar to actinium. The actinides have unfilled inner 5f electron orbitals.