Download The purpose of this packet is to prepare you for the Biology Course

Name _____________________________________________
The purpose of this packet is to prepare you for the Biology Course you will be taking in the
upcoming school year. Please read each article and work on the assignments. This packet is
due the first day of class.
Activities listed in this packet:
1. The Atom article (taken from www.chem4kids.com)
2. The Atom Guided Reading questions
3. The Periodic table article (taken www.chem4kids.com)
4. Periodic Table Guided Reading questions
5. Periodic Table Virtual Lab
6. Periodic Table of Elements
7. Periodic Table Scavenger Hunt
8. Atomic Math
9. Bohr Diagram
1
Atoms all around us
Atoms are building blocks. If you want to create a language, you'll need an alphabet. If
you want to build molecules, you will need atoms of different elements. Elements are
the alphabet in the language of molecules. Each element is a little bit different from the
rest.
Why are we talking about elements when this is the section on atoms? Atoms are the
general term used to describe pieces of matter. You have billions of billions of atoms in
your body. However, you may only find about 40 elements. You will find billions
of hydrogen (H) atoms, billions of oxygen (O) atoms, and a bunch of others. All of the
atoms are made of the same basic pieces, but they are organized in different ways to
make unique elements.
Atoms Are Building Blocks
Atoms are the foundation of chemistry. They are the basis for everything in the
Universe. As you know, matter is composed of atoms. Solids are made of densely
packed atoms while gases have atoms that are spread out. We're going to cover basics
like atomic structure and bonding between atoms. As you learn more, you can move to
the reactions and biochemistry pages and see how atoms form compounds that help
the biological world survive.
Are there pieces of matter that are smaller than atoms? Sure there are. Super-small
particles can be found inside the pieces of atoms. These subatomic particles
include nucleons and quarks. Nuclear chemists and physicists work together
at particle accelerators to discover the presence of these tiny, tiny, tiny pieces of
matter. However, science is based on the atom because it is the smallest distinct unit of
matter.
Three Easy Pieces
2
Even though many super-tiny atomic particles exist, you
only need to remember the three basic parts of an
atom: electrons, protons, and neutrons. What are
electrons, protons, and neutrons? Electrons are the
smallest of the three particles that make up atoms.
Electrons are found in shells or orbitals that surround the
nucleus of an atom. Protons and neutrons are found in the
nucleus. They group together in the center of the atom.
That's all you have to remember. Three easy pieces!
There are almost 120 known elements in the periodic
table. (117 as we write this) Chemists and physicists are
trying to make new ones every day in their labs. The atoms
of different elements have different numbers of electrons, protons, and neutrons. Every
element is unique and has an atomic number. That number tells you the number of
protons in every atom of the element. The atomic number is also called the proton
number.
Charges of Atoms
You can see that each part of the atom is labeled with a
"+", "-", or a "0." Those symbols refer to the charge of the
particle. Have you ever heard about getting a shock from a
socket, static electricity, or lightning? Those are all related
to electric charges. Charges are also found in tiny particles
of matter.
The electron always has a "-", or negative, charge. The
proton always has a "+", or positive, charge. If the charge of an entire atom is "0", or
neutral, there are equal numbers of positive and negative charges. Neutral atoms have
equal numbers of electrons and protons. The third particle is the neutron. It has a
neutral charge, also known as a charge of zero.
Since the number of protons in an atom does not change, fewer or extra electrons can
create a special atom called an ion. Cations have fewer electrons and have a positive
charge. Anions have extra electrons that create a negative charge.
Bohr Model
The Bohr Model has an atom consisting of a small, positively-charged nucleus orbited by
negatively-charged electrons. Here's a closer look at the Bohr Model, which is sometimes
called the Rutherford-Bohr Model.
3
Overview of the Bohr Model
Niels Bohr proposed the Bohr Model of the Atom in 1915. Because the Bohr Model is a
modification of the earlier Rutherford Model, some people call Bohr's Model the
Rutherford-Bohr Model. The modern model of the atom contains some errors, but it is
important because it describes most of the accepted features of atomic theory without
all of the high-level math of the modern version.
Always in Motion
As you know, electrons are always moving. They spin very quickly around the nucleus of
an atom. As the electrons zip around, they can move in any direction, as long as they
stay in their shell. Any direction you can imagine — upwards, downwards, or side wards
— electrons can do it. Electrons are constantly spinning in those atomic shells and those
shells, or orbitals, are specific distances from the nucleus. If you are an electron in the
first shell, you are always closer to the nucleus than the electrons in the second shell.
Shell Basics
Let's cover some basics of atomic shells:
1. The center of the atom is called the nucleus.
2. Electrons are found in areas called shells. A shell is sometimes called an energy level.
3. Shells are areas that surround the center of an atom.
4. The first shell can hold up to 2 electrons.
5. The second shell can hold up to 8 electrons.
6. The third shell can hold up to 18 electrons.
7. The fourth shell can hold up to 32 electrons.
4
The Atom Guided Reading Questions
1. Describe why the atom is considered the building block of all matter?
2. Complete the following table with information about the parts of the atom.
Part of the Atom
Proton
Location in the Atom
Electrical Charge
Nucleus
Negative
3. Today’s model of the atom looks different from the models that came before it. Why
do you think ideas about the structure of the atom have change over time?
4. An element has 11 electrons. Using the Bohr’s diagram below, draw the number of
electrons that will go on each orbital shell or energy level.
5
Periodic Table and the Elements
Now we're getting to the heart and soul of the way the Universe works. You know that a
generic atom has some protons and neutrons in the nucleus and
some electrons zipping around in orbitals. When those pieces start combining in
specific numbers, you can build atoms with recognizable traits. If you have eight
protons, neutrons and electrons, you will have an oxygen(O) atom. If you have seven
protons, neutrons, and electrons, you will have a nitrogen (N) atom. The atoms for
each element are unique, even though they are all made of similar subatomic parts.
Remember that 'atom' is the general term. Everything is made of atoms. The term
'element' is used to describe atoms with specific characteristics. There are almost 120
known elements. For example, you are made up of billions of billions of atoms but you
probably won't find more than 40 elements (types of atoms) in your body. Chemists
have learned that over 95% of your body is made up of hydrogen (H), carbon (C),
nitrogen, oxygen, phosphorus (P), and calcium (Ca).
The Same Everywhere
As far as we know, there are a limited number of basic elements. Up to this point in
time, we have discovered or created about 120. Scientists just confirmed the creation of
element 117 in 2014. While there are more elements to discover, the basic elements
remain the same. Iron (Fe) atoms found on Earth are identical to iron atoms found on
meteorites. The iron atoms in the red soil of Mars are also the same.
Elements as Building Blocks
The periodic table is organized like a big grid. As you move from left to right within a
period, the atomic number of each element increases by one. Elements are classified by
three major categories: metals, nonmetals, and metalloids. The zigzag line on the
periodic table can help you identify where these three classes of elements are located.
Except for hydrogen, the elements to the left of the zigzag line are metals. Metals are
elements that are shiny and conduct heat and electricity well. They are also malleable
(bend easily into any shape) and ductile (can be made into wires). The elements to the
right of the zigzag line are nonmetals. Nonmetals are poor conductors of heat and
electricity. They are also dull and brittle (can break easily). Metalloids border the zigzag
line on the periodic table. They have properties of metals and nonmetals.
You've got Your Periods...
6
Even though they skip some squares in between, all of the
rows read left to right. When you look at the periodic table,
each row is called a period (Get it? Like PERIODic table.). All
of the elements in a period have the same number of atomic
orbitals. For example, every element in the top row (the first
period) has one orbital for its electrons. All of the elements in
the second row (the second period) have two orbitals for their
electrons. As you move down the table, every row adds an
orbital. At this time, there is a maximum of seven electron
orbitals.
...and Your Groups
Now you know about periods going left to right. The periodic
table also has a special name for its vertical columns. Each
column is called a group. Elements in the same group often
have similar physical and chemical properties. The elements
in each group have the same number of electrons in the
outer orbital. Those outer electrons are also called valence
electrons. They are the electrons involved in chemical bonds
with other elements.
Every element in the first column (group one) has one electron in its outer shell. Every
element in the second column (group two) has two electrons in the outer shell. As you
keep counting the columns, you'll know how many electrons are in the outer shell. There
are exceptions to the order when you look at the transition elements, but you get the
general idea. Transition elements add electrons to the second-to-last orbital.
For example, nitrogen (N) has the atomic number seven. The atomic number tells you
there are seven electrons in a neutral atom of nitrogen. How many electrons are in its
outer orbital? Nitrogen is in the fifteenth column, labelled 'Group VA'. The 'V' is the
Roman numeral for five and represents the number of electrons in the outer orbital. All
of that information tells you there are two electrons in the first orbital and five in the
second (2-5).
Phosphorus (P) is also in Group VA which means it also has five electrons in its outer
orbital. However, because the atomic number for phosphorus is fifteen, the electron
configuration is 2-8-5.
Two at the Top
7
Hydrogen (H) and helium (He) are special
elements. Hydrogen can have the electron traits of two
groups: one and seven. For chemists, hydrogen is
sometimes missing an electron like the members of group
IA, and sometimes has an extra one as in group VIIA.
When you study acids and bases you will regularly work
with hydrogen cations (H+). A hydride is a hydrogen anion
and has an extra electron (H-).
Helium (He) is different from all of the other elements. It is very stable with only two
electrons in its outer orbital (valence shell). Even though it only has two, it is still
grouped with the noble gases that have eight electrons in their outermost orbitals. The
noble gases and helium are all "happy," because their valence shell is full.
Calculating Protons, Electrons, and Neutrons
1. Get the periodic table of elements. The periodic table is a chart that organizes
elements by atomic structure.
2. Locate the element’s atomic number. The atomic number is located above the
element symbol, in the upper left-hand corner of the square. The atomic number will tell
you how many protons make up a single atom of an element. For example, boron (B)
has an atomic number of 5, therefore it has 5 protons.
3. Determine the number of electrons. Protons are particles in the nucleus of an
atom that have a positive charge. Electrons are particles that have a negative charge.
Therefore, an element in a neutral state will have the same number of protons and
electrons. For example, boron (B) has an atomic number of 5, therefore it has 5 protons
and 5 electrons.
4. Look for the atomic mass of the element. To find the number of neutrons, you
will first need to find the atomic mass. An element’s atomic mass (also known as the
atomic weight) is the average mass of atoms of an element. The atomic mass can be
found underneath the symbol for the element. Make sure that you round the atomic
mass to the nearest whole number. For example, the atomic mass of boron is 10.811,
but you can just round the atomic mass up to 11.
5. Subtract the atomic number from the atomic mass. To find the number of
neutrons, you will need to subtract the atomic number from the atomic mass.
Remember that the atomic number is the same as the number of protons, which you
have already identified. For our boron example, 11 (atomic mass) – 5 (atomic number)
= 6 neutrons
8
Periodic Table Guided Reading Questions
1. Describe the organization of the periodic table.
2. How are periods and groups different from each other?
3. Label the information provided on the periodic table.
4. What does the atomic number represents?
5. What does the atomic mass represents?
6. Use your knowledge of the periodic table to complete the chart.
9
The Periodic Table Virtual Lab
Website: www.msbutlerscienceclass.com
How is an atom's structure related to its position on the periodic table? In the late 1800s, Dmitri
Mendeleev, a Russian chemist, arranged all the elements known at that time in the order of
increasing atomic masses. He discovered that there was a pattern to the properties of the
elements. This arrangement of elements according to repeated changes in properties is called a
periodic table of elements.
The periodic table is arranged in rows and columns. The columns are called groups, or families.
The horizontal rows of elements in the periodic table are called periods.
All the elements to the left of the stair-step line on the right of the periodic table are metals.
Most of them have common properties. The elements to the right of the stair-step line on the
periodic table are classified as nonmetals. The elements next to the stair-step line are metalloids
because they have properties of both metals and nonmetals. Elements in groups 3 through 12
are called the transition elements. They are metals but have properties not found in elements of
other groups.
In this Virtual Lab, you will explore the relationships among families and periods of elements.
Objectives:
Describe the periodic table of elements and use it to find information about elements. ‡
Compare selected elements from the periodic table.
Explore families and periods on the periodic table.
Procedure:
1. Choose a family from the periodic table that you would like to learn about. Then, select
several elements from that family, one at a time by clicking each element's box on the table.
Open the table and record data about the element in the appropriate place in the table.
2. Review the data you collected from the family of elements. Decide how the elements compare
and record this information in your Journal.
3. Repeat steps 1 and 2 with a period of elements.
4. Click across a row of elements, one at a time. Observe what happens to the atomic number
and record it in your Journal.
5. Choose four elements from anywhere in the periodic table. Record their masses in the table.
Explain how their masses relate to each other and their positions on the table and record this in
your lab sheet.
10
Periodic Table Data
Element
Symbol
Element
Name
Atomic
Number
Atomic
Mass
State of Matter
Conclusion:
1. How do the elements in the family you chose compare?
2. How do the elements in the period you chose compare?
3. What happens to the number of protons in an element as you click across a row?
4. How do the masses of your four chosen elements relate?
5. How would you explain the way the periodic table is arranged?
11