Name: ___________________________________ Date: _________________ Class period: ____
Quarter 2 Study Guide
Chemistry Quarter 2
Ionic Compounds
The charge of an element’s ion is determined by the group (column) the elements are in.
Group #
1
2
13
14
15
16
17
18
Charge
+1
+2
+3
+4 / -4
-3
-2
-1
0
How to write chemical formulas for ionic compounds
Method 1
1.
2.
3.
4.
Figure out what ions the elements form.
Figure out how many ions you need for each element.
Write the metal, then the nonmetal.
Write the subscripts that you figured out in #2.
Method 2 -- the criss-cross method. To find the subscripts, switch the numbers of the ions’
charges to the opposite element.
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How to write names for ionic compounds
1.
2.
3.
4.
Figure out which elements are in the chemical formula.
Write the name of the metal first.
Write the name of the nonmetal.
Change the ending of the nonmetal to –ide.
Example:
2
Covalent Compounds
How to write names for covalent compounds
1. Use the prefixes to indicate how many of each element is in one molecule.
2. Change the ending on the second element to -ide.
How to write chemical formulas for molecular compounds
1. Split each word into two parts: prefix and chemical name.
2. Use the prefixes to determine the subscripts for each chemical symbol.
How to draw Lewis dot structures
The number of valence electrons are determined by the group (column) the elements are in.
Octet rule: atoms will bond with each other to get 8 valence electrons.
3
1.
2.
3.
4.
H
Group 14
Group 15
Group 16
Group 17
# of valence
electrons
1
4
5
6
7
# of electrons
short
1
4
3
2
1
# of bonds
made
1
4
3
2
1
Draw each atom with the correct number of dots.
Rearrange the atoms so that the single dots of each atom are next to each other.
Pair up the dots by circling them.
Redraw the Lewis dot structure by replacing the circled dots with lines to represent
bonds.
Example:
4
States of Matter
Gases
●
●
●
●
●
●
●
●
●
Gases are made up of tiny particles.
Gas particles don’t attract or repel each other.
Gas particles can flow.
Gases have no definite volume.
Gas particles move very fast and independently of each other.
“Random walk” - gas particles move in a straight line until they collide.
All collisions between gas particles are elastic. The particles don’t stick together.
Gases are very compressible.
Gas particles have the greatest kinetic energy.
Liquids
●
●
●
●
Liquids move as a unit due to intermolecular forces.
Intermolecular forces keep liquid particles close together.
Liquid particles can flow.
Liquids are not easily compressible.
Solids
●
●
●
●
Solids have the lowest kinetic energy.
The intermolecular forces are highest in a solid.
Solid particles are in fixed positions. They vibrate in place and do not flow.
Two types of solids: crystalline, amorphous
Phase changes
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Example:
6
Claim, Evidence, Reasoning
Used to answer a question in 5 sentences with evidence.
Written in the following format:
● Claim: write down the answer to the question. My claim is _______________________.
● Evidence 1: write down what you see, NOT what you think. My first piece of evidence
is ________________________________________________________________________.
● Evidence 2: same as above, must be different from Evidence 1. My second piece of
evidence is ________________________________________________________________.
● Evidence 3: same as above, must be different from Evidence 2 and 3. My third piece of
evidence is ________________________________________________________________.
● Reasoning: the scientific principle that’s always true. I know that _________________.
●
Conclusion: apply the scientific principle to the question, restate the claim. My
evidence says ______________________________________________________________.
Therefore, _________________________________________________________________.
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