Grade 9 Chemistry review Atoms, Subatomic Particles, Diagrams …

Learning goals We are learning to calculate subatomic particles. We are learning to draw Bohr and Lewis dot diagrams. We are learning to calculate charges on ions.

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: Hydrogen Carbon Neon

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: Nitrogen Helium Fluorine Oxygen

ions Atoms that have an unequal amount of protons and electrons are called ions. Two types: Cations (positive ions): # of electrons < # of protons Anions (negative ions): # of electrons > # of protons Metals form cations Non-Metals form anions.

sodium Draw Sodium’s Bohr diagram Draw Sodium’s Bohr Ion diagram Draw Neon’s Bohr diagram

fluorine Draw Fluorine’s Bohr diagram Draw Fluorine’s Bohr Ion diagram Draw Neon’s Bohr diagram

Aluminum & Sulfur You try it with your elbow partner!!! Draw Bohr diagram and Bohr Ion diagram

Naming ions Cations Anion Positive charge Sodium  sodium ion Na1+ Negative charge Fluorine  fluoride F1-

Learning goals We are learning to calculate subatomic particles. We are learning to draw Bohr and Lewis dot diagrams. We are learning to calculate charges on ions.

Please complete P187 #1, 3, 4, 5, 7, 8 P191 #2, 4, 5, 6, 7, 8