Patterns & the periodic table Atoms, Subatomic Particles, Diagrams …

Learning goals We are learning patterns and arrangements of the periodic table. We are learning to draw Bohr and Lewis dot diagrams.

The periodic table ELEMENT: a pure substance that cannot be broken down.

organization

organization

organization Groups: The vertical columns of a periodic table. These are elements with similar properties. Identifies number of electrons in outer shell  valence electrons Periods: The horizontal rows of a periodic table. Identifies the number of shells in the atom

The groups Alkali Metals (Group I): Soft highly reactive metals. Alkaline Earth Metals (Group II): light, reactive metals Halogens (Group XVII): One of the most reactive groups on periodic table. Noble / Inert Gases (Group XVIII): Very stable, rarely react with other chemicals.

The atom The smallest building block of matter. Contains three sub-atomic particles: Proton (p+): Positively charged, inside the nucleus. Neutron (no): No charge, inside the nucleus. Electron (e-): Negatively charged, in shells around the nucleus. In neutral atoms, #protons = #electrons

Do you remember??? element name atomic number element symbol atomic mass

Whoa!!! Atomic Number = Protons = Electrons Neutrons = Atomic Mass – Protons Isotope – same elements with different numbers of neutrons thus have a different mass C-12 and C-14 (number indicate the mass)

With your elbow partner Find the element symbol, atomic mass, atomic number, protons, electrons, and neutrons for the following elements: Magnesium Hydrogen Chlorine

Bohr diagrams Draw the nucleus Write the number of protons and neutrons in the nucleus Draw first ring (max 2 electrons in this ring) Add electrons Draw second ring (max 8 electrons in this ring) Draw third ring if needed (max 8 electrons in this ring)

Your turn… With your elbow partner, draw Bohr diagrams for the following: Lithium Nitrogen Helium

Lewis diagrams Shows valence electrons only Draw element symbol and add valence electrons starting at 12 o’clock With your elbow partner, draw Lewis diagrams for following elements: Phosphorous Neon Chlorine Aluminum

Learning goals We are learning patterns and arrangements of the periodic table. We are learning to draw Bohr and Lewis dot diagrams.

Please complete P187 #1, 3, 4, 5, 7, 8