Tuesday, March 24 Pick up a notes slip and glue it into your comp book Take out your packet and open to pages 6-7. Review the information on these pages to preview what you are learning today.
Brainpop Video Clip: Chemical Bonding While watching, think about bonding and the two main types (ionic and covalent). After the Video, Round Robin share with your team one thing you learned from the video until you run out of things to share.
Ionic and Covalent Bonding Notes
Stable or Unstable? An atom is only stable if it has a full valence shell If an atom is stable, it will not bond If an atom is not full, it will bond
Compounds Compounds are formed when 2 atoms of different elements bond together. Atoms bond to fill their valence shell An atom will bond with an many atoms as it takes to fill its outer shell Once the valence shell is full, that atom is stable
Types of Chemical Bonds There are two types of chemical bonds: Ionic Bonds Covalent Bonds
Ionic Bonds Ionic bonds exist between a non- metal and a metal When two atoms bond ionically, they gain/lose electrons When an atom gains or loses an electron, it becomes an ion (an atom with a positive or negative electrical charge)
Ions Ca +2 +2 +2 +2 +2 +2 +2 It has 2 valence electrons. How many does it need to be stable? Which other elements would lose 2 electrons? 8…so it can either lose 2 or gain 6. Which is easier? Calcium is in group 2. How many valence electrons does it have? Group 1 18 2 13 14 15 16 17 3 4 5 6 7 8 9 10 11 12 Losing 2…if it loses 2 electrons, it becomes positive Ca +2 +2 +2 +2 +2 +2 +2
Ions +1 +1 +2 +3 +4 -3 -2 -1 +1 -2 +2 +3 +4 -3 -1 +1 -2 +2 +3 +4 -3 -1 Group 1 18 2 13 14 15 16 17 3 4 5 6 7 8 9 10 11 12 +1 +1 +2 +3 +4 -3 -2 -1 +1 -2 +2 +3 +4 -3 -1 +1 -2 +2 +3 +4 -3 -1 +1 +2 +3 +4 -3 -2 -1 +1 +2 +4 -3 -2 -1 +3 +1 +2
Types of Ions Cation Positive Metals loses/gives away valence electrons) Anion Negative Nonmetals gain/take valence electrons)
Cation Positive ion (a metal gives away electrons in ionic bonding and becomes positively charged) Anion Negative ion (a nonmetal takes electrons in ionic bonding and becomes negatively charged)
Covalent Bonds Covalent bonds exist between NONMETAL and NONMETAL. Example: H2, H2O, NO3, CH4 Covalent bonds SHARE electrons. Shared electrons don’t belong to either atom.
Covalent Bond (2 non-metals)
Lewis Dot Diagram Review Draw the valence electrons up to 8! Then show the bonding. Write the charges/ions for ionic bonds.
CH4
Writing Chemical Formulas – Ionic Bond The cation (metal) is always written first in the formula, like Sodium in Sodium Chloride (NaCl) Write the ion charges Cross them down and write them as a subscript
Formulas of Ionic Compounds In order for ionic compounds to be electronically neutral, the sum of the charges on the cation and anion in each formula must be zero. Aluminum oxide: Al3+ O2– Al2O3 Sum of charges: 2(+3) + 3(–2) = 0
To Do: Complete the “Bonding Basics” practice in your packet. Draw the bonds, as specified Write the chemical formula for each compound Extra Challenge: Follow the instructions in your packet to try and write the correct names for each compound. If finished early, start reading about Acids and Bases on the next page in your packet and READ pages 214-217 in your textbook. Then start answering the Acid and Base questions in your packet.