Name
Date
Class
Atoms, Bonding, and the Periodic Table
1. What does an element’s atomic number represent?
2. In an atom, how are the number of protons and the number of electrons related?
3. APPLY CONCEPTS The atomic number for nitrogen (N) is 7. How many
electrons are in a nitrogen atom?
4. APPLY CONCEPTS The element immediately below nitrogen in the
periodic table is phosphorous (P). The atomic number for
phosphorous is 15. How many electrons are in a phosphorous atom?
5. DEFINE What are valence electrons?
b. EXPLAIN Why do the properties of elements change ina regular way across the rows(periods) of the
Periodic Table.
c. RELATE CAUSE AND EFFECT Explain the reactivity of the noble gases in
terms of valence electrons.
129A
Name
Date
Class
Atoms, Bonding, and the Periodic Table
What Determines an Element’s Chemistry?
1a. DEFINE What are valence electrons?
b. EXPLAIN Why do the properties of elements change in
a regular way across a period?
c. RELATE CAUSE AND EFFECT Explain the reactivity of the noble gases in
terms of valence electrons.
I get it! Now I know that the chemical properties of an element are determined
by
I need extra help with
129B
Name
Date
Class
Atoms, Bonding, and the Periodic Table
129C
Name
Date
Class
Atoms, Bonding, and the Periodic Table
Understanding Main Ideas
Look at the diagram below. Then answer the following questions in the space provided.
1. How many protons does a nitrogen atom have?
2. How many valence electrons does a nitrogen atom have?
3. Is nitrogen reactive or stable?
4. Neon (Ne), which has an atomic number of 10 is in Group 18 in the periodic table. To which
group does nitrogen belong?
5. The element directly below nitrogen in the periodic table is phosphorous (P). How many
valence electrons does phosphorous have?
6. Will the properties of nitrogen be more similar to the properties of neon or the properties
of phosphorous? Explain.
Building Vocabulary
If the statement is true, write true. If the statement is false, change the underlined word
or words to make the statement true.
7.
An element’s reactivity is determined by the
number of protons found in an atom of the element.
8.
The force of attraction that holds two atoms
together is called a chemical bond.
9.
In a(n) periodic table, dots around an
element’s symbol indicate the number of valence electrons in
an atom.
129D
Name
Date
Class
Atoms, Bonding, and the Periodic Table
Read the passage, look at the diagram, and study the table. Then use a separate sheet of
paper to answer the questions that follow.
The Rockets’ Red Glare
The basic fireworks unit is called a shell,
and it is packed with chemicals that produce
light, smoke, and noise when they burn.
The effects depend on which chemicals
are packed into the shell and how they are
arranged.
A simple shell is shown at the right. When
the gunpowder is at the bottom of the shell
is lit, it explodes and lifts the shell into the air.
By the time the shell has reached the high point of its path, a second fuse ignites the other chemicals.
Some shells explode all at once. Others are made of smaller shells that burst apart and explode
separately. Time delays can be used to make a shell explode in stages.
The table below lists some chemicals and the effects they produce.
Element
Effect
strontium or lithium
red color
barium
green color
copper
blue color
sodium
yellow color
magnesium or aluminum
white color
potassium or sodium
whistling sound
potassium and sulfur
white smoke
Please answer questions on the back.
To which groups of the periodic table do the majority of the
elements listed in the table above belong? Why do you think
elements in these groups are used in making fireworks?
2. Which group of elements could you not use in making fireworks?
Explain your answer.
3. Why would you want to have two or more separate fuses in a rocket?
4. Solutions of magnesium, barium, and strontium are clear and
colorless. Predict what might happen if a drop of each solution was
held in the flame of a lab burner.
1.
129E
Name
Date
Class
Atoms, Bonding, and the Periodic Table
If the statement is true, write true. If the statement is false, change the underlined word
or words to make the statement true.
An atom’s valence electrons are those electrons that have the
1.
highest energy.
2.
Atoms tend to be stable and nonreactive if they have six
valence electrons.
3.
In the periodic table, the number of valence electrons in each
element decreases from left to right across each period.
4.
The reactivity of a metal depends on how easily it loses its
valence electrons.
5.
Within each period in the periodic table, elements have similar
properties because they have the same number of valence electrons.
Fill in the blank to complete each statement.
6. The number of
determines its chemical properties.
in the atom of an element
7. The columns in the periodic table are called
.
8. A(n)
electrons in an atom in pictorial fashion.
shows the number of valence
9. The attractive force that holds two atoms together is called a(n)
.
10. Because it can either lose or share electrons when it combines with other elements,
each
has some of the properties of metals and some of the
properties of nonmetals.
129F
Atoms, Bonding, and the Periodic Table
Answer Key
1. the number of protons in one atom of the
1. Groups 1 and 2; because they are very reactive
element
2. the noble gases; because they do not react
2. They are the same.
easily
3. 7
3. You need one fuse to ignite the gunpowder
that sends the rocket into the air, and other
fuses to ignite the chemical compounds that
produce the light and noise once the rocket has
reached its maximum height.
4. 15
4. The element in solution might burn as it does in
Barium: “Ba” with 1 dot above it and 1 dot to its
right
Carbon: “C” with 1 dot on each of its 4 sides
Cesium: “Cs” with 1 dot to the right of it
Iodine: “I” with 1 dot below it and 2 dots on each
of the other three sides
Krypton: “Kr” with 2 dots on each of its 4 sides
Phosphorous: “P” with 2 dots to its right and
1 dot on each of its other 3 sides
Strontium: “Sr” with 1 dot above it and 1 dot to
its right
a firework rocket, giving off a color. The results
could be used to tell the solutions apart.
1. true
2. eight
3. increases
4. true
5. group
6. valence electrons
7. groups
8. electron dot diagram
9. chemical bond
1. 7
2. 5
3. reactive
4. Group 15
5. 5
6. Nitrogen’s properties will be more similar
to the properties of phosphorous because,
unlike neon, both elements are in the same
group and have the same number of valence
electrons.
7. valence electrons
8. true
9. electron dot diagram
129G
10. metalloid
129H