Unit 2 Problem Set
From Atoms to Molecules and Compounds
Name: __________________________
Date: ___________________________
Learning Objectivs ():
My Three Specific, Measurable, Attainable, Relevant, and Time Based (SMART)
Goals for this test are (make sure at least one is about how well you do!) (2
points):
1.
2.
3.
1
Unit 2 Problem Set
From Atoms to Molecules and Compounds
Use the words from the word bank to fill in the blanks. You will use every word
once. (15 points).
molecule
metallic bond
ionic bond
compound
valence
displacement
synthesis
crystal
polymer
endothermic
physical process
ion
exothermic
covalent bond
decomposition
1)
In a ______________________________, which might include a change of
state or dissolving, most of the properties of the atoms, molecules, or compounds
stay the same.
2)
When a ______________________________ forms, electrons are shared by
nonmetals.
3)
Every __________________________ is also a molecule because when you
have at least two elements with at least one atom each, you have at least two atoms.
4)
The ________________________ electrons are the most important electrons
because they are on the outer edges of the atom.
5)
___________________________ reactions occur when an atom in a reactant
trades places and joins a new compound in a product.
6)
A ___________________________ is formed when two or more atoms (from
any elements) bond with each other.
7)
A _________________________ is a long chain of many molecule “parts” that
are held together by covalent bonds.
8)
In a ___________________________ reaction, one reactant breaks down into
two or more products.
9)
Heat is absorbed in an _____________________________ chemical reaction.
10)
In a ______________________________________, every atom wants to give
electrons and nobody wants to gain, which leads to a “sea of electrons” that
surround all the atoms.
11)
When heat is a liberated in a chemical reaction, we call that reaction
______________________________.
12)
When a metal wants to give electrons and a nonmetal wants to get electrons,
they come together in an ______________________________.
13)
When an atom gains or loses an electron, it becomes an __________ and has a
charge.
2
Science
Test – From Atoms to Molecules and Compounds
14)
Even though it can be formed by atoms, molecules, or ions coming together in
any type of bond, a ___________________________ will always be arranged in an
orderly pattern.
15)
In a _________________________ reaction, two or more reactants join
together to form a single product.
Answer the questions below in complete sentences.
16)
How many valence electrons do most elements want to have, and why? (3
points
17)
How many atoms of which elements are in 1 molecule of F6NP3? (2 points).
18)
How many atoms of which elements are in 1 molecule of H3AsO4? (2 points).
Draw valence electron dot diagrams for the following elements (4 points).
19)
Potassium
21)
Phosphorus
20)
Radon
22)
Bromine
3
Science
Test – From Atoms to Molecules and Compounds
23)
Draw a metallic bond between four iron atoms that have three valence
electrons each. (4 points).
Draw dot and line diagrams for the covalent bonds below. Show all your work!
24)
Br2 (7 points).
a. How many atoms of what elements are in it?
b. Is this a molecule, a compound, or both (circle)?
COMPOUND
MOLECULE
c. Draw the valence electron diagrams separately and for each atom, write down
how many valence electrons it needs.
c. The covalent bond dot diagram:
25)
d. the covalent bond line diagram:
CS2 (8 points).
a. How many atoms of what elements are in it?
4
Science
Test – From Atoms to Molecules and Compounds
b. Is this a molecule, a compound, or both (circle)?
COMPOUND
MOLECULE
c. What is its scientific name?
d. Draw the atom dot diagrams separately and for each atom, write down how many
valence electrons it needs.
e. The covalent bond dot diagram:
f. the covalent bond line diagram:
Draw a full diagram for an ionic bond below. Show all your work!
26)
Draw Lithium Monofluoride (LiF) as a full diagram: (10 points).
a. atom that gives:
b. wants to be like:
c. so gives:
d. atom that gets:
e. wants to be like:
f. so gets:
5
Science
Test – From Atoms to Molecules and Compounds
g. compound after ionic bond:
For the following questions, remember the difference between physical
processes and chemical reactions! A physical change is the same as a physical
process, and a chemical change is the same as a chemical reaction.
27)
Which is a chemical change? (1 point).
a. Paper is shredded
b. Liquid wax turns solid
c. A raw egg is broken
d. Soap scum forms on your drain
28)
Each procedure below results in the formation of bubbles. Which is a
physical change? (1 point).
a. Pouring an acid onto a metal
b. Dropping some antacid into water
c. Heating water to its boiling point
6
Science
Test – From Atoms to Molecules and Compounds
d. Pouring vinegar into baking soda
29)
Which of the following is true about cooking an egg? (1 point).
a. It is an endothermic chemical reaction because the egg absorbs the
heat
b. It is an exothermic chemical reaction because the egg absorbs the heat
c. It is an endothermic chemical reaction because the egg releases heat
d. It is an exothermic chemical reaction because the egg releases heat
30)
Preparing a meal involves both chemical changes and physical changes.
Which is a chemical change? (1 point).
a. Boiling water
b. Making ice cubes
c. Slicing a carrot
d. Toasting bread
31)
Which description does NOT describe a physical property? (1 point).
a. Burns in air
b. Has a blue color
c. Melts at room temperature
d. Is 10 cm long
BONUS: Fill out the chart with what the prefixes mean and name the compounds
given by the formula. Spelling counts! (5 points).
Prefix
Meaning
Prefix
mono-
hexa-
di-
hepta-
tri-
octo-
tetra-
nona-
penta-
deca-
32)
C4S2
33)
OF ________________________________________________
Meaning
________________________________________________
7
Science
Test – From Atoms to Molecules and Compounds
34)
S4O4 ________________________________________________
35)
C3O6 ________________________________________________
36)
N5I5 ________________________________________________
Now write the chemical formulas for compounds given by their scientific names.
37)
Diphosphorus dioxide ____________
38)
Selenium Monobromide ____________
39)
Fluorine Hexabromide ____________
40)
Tricarbon Dioxide ____________
41)
Nitrogen tetrafluoride ____________
Did you meet your goals for today? For each of the three goals you wrote on the
front page, write whether you achieved it and why or why not. For the goal
about how well you did, write whether you think you got there and why. (2
points)
1.
2.
3.
8