Name:
Homework 1
Purple Due Monday 4/15 & Green Due Tuesday 4/16
Bonding
1) How do bonds form? When atoms share/exchange electrons between each other
2) What occurs when bonds are broken ad reformed? A reaction occurs!
Ionic vs. Covalent Bonding
Fill in the blank with ionic or covalent
1. This bond is formed between metals and non-metals.
ionic
2. This bond type of bond is why we have electricity!
ionic
3. This bond is formed because of electron sharing.
covalent
4. Attraction between cations and anions.
ionic
5. This bond is formed between non-metals only.
covalent
Classify each compound as ionic or covalent.
6. NaF
ionic
13. Beryllium oxide
ionic
7. CuCl2
ionic
14. Carbon dioxide
covalent
8. NO2
covalent
15. Sodium chloride
ionic
9. Cl2
covalent
16. Boron trifluoride
covalent
10. H2O
covalent
17. Lithium fluoride
ionic
11. CaO
ionic
18. Magnesium sulfide ionic
19. Which of the following substances is most likely to react with chlorine (Cl) to form an ionic compound.
A.
Neon (Ne)
B.
Carbon (C)
C.
Oxygen (O)
D.
Potassium (K)
Why?
Because to form an ionic compound a nonmetal and a metal must bond. Also potassium will freely give up its 1
valence electron in order to make chlorine have 8 valence electrons
20. Which of the following substances is most likely to react with sulfur (S) to form a covalent compound.
E.
Neon (Ne)
F.
Cobalt (Co)
G.
Oxygen (O)
H.
Potassium (K)
Why?
Because to form a covalent compound two nonmetals must bond. The only nonmetals listed are oxygen and neon.
Only oxygen will form a bond though because Neon has 8 valence electrons and so has no need to bond.
21. Neon is a non-metal. Explain why it won’t combine with Sulfur to form a covalent compound.
Neon will not combine with sulfur because it has 8 valence electrons, thus has no need to form bonds in order to
become full and stable and happy.
22. Explain what electrons do in ionic compounds.
Ionic compounds transfer an electron from one element to another.
23. Explain what electrons do in covalent compounds.
Covalent compounds share electrons between atoms.
24. Directions: Draw the ionic bond between each of the following elements. Be sure to show all valence electrons and
ionic charges.
Lithium & Bromine
Magnesium & Oxygen
3 Lithiums & 1 Nitrogen
Magnesium & 2 Chlorines
25. Directions: Draw the covalent bond between each of the following elements. Be sure to show all valence electrons
and ionic charges.
Bromine & Bromine
Oxygen & Oxygen
2Hydrogens & Oxygen (Oxygen goes in the
middle)
1 Silicon & 4 Fluorines (Si goes in the middle)
26. Complete the following steps to determine what compound formula is created when Potassium (K) and Sulfur (S)
bond.
Step 1: Determine the number of valence
electrons for K and S
Step 2: Determine what ions K and S will
form
K=1
K+1
S=6
Step 3: Match your elements to make a
neutral compound
S-2
Step 4: Can you simplify?
No!
K2S
27. Determine the ionic formulas created when the following pairs of elements bond:
a. Magnesium and Chlorine
MgCl2
b. Potassium and Chlorine
KCl
c. Cesium and Phosphorous
Ce3P2
d. Barium and Silicon Ba2Si
e. Sodium and Oxygen Na2O
Chemical vs. Physical Properties
1. Which of the following represent a chemical property?
a.
b.
c.
d.
density
mass/weight
reactivity
color
2. List 4 physical properties of water.
Liquid, translucent (clear), density of 1g/mL, takes the shape of its container
Chemical vs. Physical Reactions
1. When observing a reaction, what are indicators that help show a reaction has actually occurred?
Color change, light emitted, change in temperature, smell, something new is created, irreversible
2. When watching an ice cube melt, is that a chemical or physical change? Explain how you know.
A physical change because all that has occurred is a solid has turned into a liquid (a change in state/phase). Also it is
reversible
3. Ozone (O3) is able to attract weak magnetic fields while O2 cannot. Is this a chemical or physical difference? Chemical