5
CHAPTER REVIEW
ACHIEVEMENT CHART CATEGORIES
t Thinking and investigation
k Knowledge and understanding
c Communication
11. Examine the photograph of mercury at
room temperature and answer the questions
that follow.
a Application
Key Concept Review
1. What is the smallest amount of an element
that can exist? k
2. Compare and contrast the charge, the
location in an atom, and the relative mass
of an electron with those of a neutron. k
Question 11
3. Beginning with the innermost shell, list the
maximum number of electrons that an atom
can have in its first three shells. k
(a) What properties of mercury would have
led early chemists to classify it as a
metal? Explain. c
4. List three halogens, and describe a property
that they all share. k
(b) What property makes mercury different
from most other metals? k
5. (a) What is the Latin name for lead?
(b) What is the symbol for lead?
12. (a) List two properties that generally
increase, beginning with the first
element in the periodic table through to
the 100th element and beyond. k
k
k
6. Name four non-metals that are solids at
room temperature. k
7. What is the difference between an insulator
and a conductor? Give an example of an
element that is a weak conductor. k
8. (a) If an atom has 43 protons, what element
is it? k
(b) If an atom contains 66 electrons, what
element is it? k
9. Use Figure 5.45 on page 198 to answer the
following questions.
(a) How many shells containing electrons
does a potassium atom have? k
UNIT B
Atoms, Elements, and Compounds
13. The symbol for gold is Au, based on the
Latin term aurum. Is there any reason why
Go could not have been chosen as the
symbol for gold? t
14. How did Dmitri Mendeleev use the
estimated mass of atoms to help him to
order the elements in a table? a
(b) Name three uses for the element that
you listed in (a). a
(c) Name the element that has a full
valence shell of two electrons. k
206
Connect Your Understanding
15. (a) What element is diamond made of?
What is the name of another pure form
of this element? k
(b) How many valence electrons does a
calcium atom have? k
10. Draw a Bohr diagram of a chlorine atom.
(b) Are there any exceptions to the pattern
described in (a)? Explain. k
c
(c) What are some environmental issues
related to using the element that you
listed in (a)? a
16. Mendeleev believed that one of the gaps in
his first periodic table would eventually be
filled by an element he called eka-silicon.
Such an element had not yet been
discovered. In 1871, he predicted what the
properties of this undiscovered element
would be. In 1886, he was found to be
correct.
Use the information in the figure and table
below to answer the following questions.
14
Si
atomic mass
14
12
28.1
31
13
Ga
32
14
12
“Eka-silicon”
69.7
33
?
50
Sn
3
15
As
17. In the early 1800s, just over 30 elements
had been identified. Today, there are more
than 100 known elements. Why might there
have been such a rapid increase in the
discovery of elements? t
18. In the last 50 years, many new elements
have been made in laboratories. How do the
numbers of subatomic particles in atoms of
these elements compare to the numbers in a
common element such as iron? a
19. Create a warning poster or public service
announcement about an element that can
cause harm if improperly used or stored. c
74.9
12
14
Reflection
118.7
20. Now that you have studied atomic theory,
how has your understanding of the
composition of matter changed? c
Question 16
Properties of Selected Elements
Atomic
Mass (amu)
Element
Colour
silicon
steel grey
28.09
gallium
grey-black
69.72
eka-silicon
?
arsenic
silver to grey-black,
sometimes yellow
tin
grey-white
21. Briefly describe three ways in which pure
elements are used that you did not know
about before reading this chapter. c
?
74.92
118.71
(a) Which of the four elements in the figure
would you use to predict the properties
of Mendeleev’s new element? Explain
your reasoning. t
(b) Approximately what atomic mass would
you predict for eka-silicon? t
(c) What colour would you predict ekasilicon to be? t
(d) What do we now call eka-silicon?
t
(e) Mendeleev did not predict an atomic
number for eka-silicon. Why not? a
After Reading
Reflect and Evaluate
Summarize the “fix-up” strategies you learned to
use in this chapter. Working with a partner, create
a tips sheet for other readers about fixing up
understanding when they are reading. Add other
strategies that you have used successfully to
understand what you read.
Unit Task Link
Use your knowledge of the properties of the
elements to explain why pure elements would not
be used as toothpaste ingredients. Identify
elements that you would not want to add to
toothpaste, even if these elements were in the
form of compounds.
The periodic table organizes elements by patterns in properties and atomic structure.
207