UNIT 1.8 VALENCE ELECTRONS AND IONIC COMPOUNDS
Chemistry is the study of matter and interactions. Chemistry overlaps with many other sciences.
Below is the contents for this sub unit. If you have taken Chemistry 1, this should all be review but it is always good to brush up on the basics (significant figures especially).
VALENCE ELECTRONS AND IONIC COMPOUNDS
As we come to the end of unit 1 there are only a few new items (some we touched on in Chem 1). So please take the time to review these is you haven't yet. Yes some I have listed before
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Review 'History of the Atom' for introduction of the atom and periodic trends
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Review 'Orbitals and Electron Configuration' for introduction of electrons
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And for this section review 'Naming Compounds' (specifically ionic) for introduction of ionic bonds
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Valence Electrons - electrons in the outer ring (orbital). These are the electrons that react. Remember a completed shell tends to be stable (noble gas).
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Ionic Compound - a compound that transfers the electron from one atom to another then held together by charge difference.
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Ionic compounds are typically a metal to a non-metal. The metal loses electrons (becoming positive). The non-metal takes the electrons (becoming negative). Then the opposite charges attract.
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Examples:
NaCl
KCl
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These are similar (analogous) compounds. The metals are both from group 1 on the periodic table thus they have similar properties.
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These compounds are likely to form as the K and Na want to get rid of 1 electron and the Cl wants 1 electron. While CaCl2 will form, it requires 2 chlorine atoms to react thus is less likely.
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