BONDS

EXPECTATIONS: -- Before we start this unit you should:

  • Understand basic atomic structure including the mass, charge and location of electrons, protons and neutrons

  • Understand that certain atoms gain electrons to form negative ions

  • Understand that certain atoms lose electrons to form positive ions

LEARNING GOALS: At the conclusion of this unit, students will be able to:

PART I: Ionic Bonds

  1. Explain how ions and ionic bonds are formed.

for example:

  • sodium atoms lose an electron to become a positive ion (Na+1 which we name sodium ion)

  • chlorine atoms gain an electron to become a negative ion (Cl-1which we name chloride ion)

  • those charged ions are then attracted to each other and form bonds to create the ionic compound sodium chloride.

2) Explain the meaning of a chemical formula for an ionic compound such as MgCl2

  • The charges in an ionic compound MUST balance to zero.

  • Magnesium loses 2 electrons to form an ion with a +2 charge.

  • Chlorine gains an electron to form an ion with a -1 charge.

  • It takes 2 chorlide ions (each of -1 charge) to balance 1 magnesium ion with its' +2 charge

  • Therefore one atom of magnesium is present and 2 atoms of chlorine are present in the ionic compound magnesium chloride.

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PART II: Covalent Bonds

  1. Give examples to illustrate that molecules are groups of two or more atoms bonded together (for example: a molecule of carbon dioxide is formed when one carbon atom shares electrons with two oxygen atoms in a covalent bond).

  2. Explain the meaning of a chemical formula for a molecule (for example the molecule carbon tetrachloride: CCl4).
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    PART III: Chemical Reactions

1) Use a chemical equation to illustrate how the atoms in molecules are arranged before and after a reaction.cccccc

2) Give examples of chemical reactions that either release (exothermic) or acquire energy (endothermic) and result in the formation of new substances (for example: burning of fossil fuels releases large amounts of energy in the form of heat).

3) Predict the effect of a change in temperature, surface area, or pressure on the rate of a chemical reaction (See RATE OF REACTIONS LAB)

 

VOCABULARY: Click HERE to go to see a list of vocabulary terms for the BONDS unit

STUDY GUIDES:

► Click HERE to go to Bonds Unit study guide

VIDEOS:
  Making sodium chloride (this is a *very* violent process!)

DOCUMENTS:

►  Mr W Periodic Table

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