Download Lesson #3 - How to use the periodic table to determine the symbol

Lesson #3 - How to use the periodic table to determine the symbol, name, number of
protons, number of neutrons, number of electrons, atomic mass and the electron
configuration of an atom
Virginia SOLs
PS.4 The student will investigate and understand the organization and use of the periodic
table of elements to obtain information. Key concepts include
a.
symbols, atomic number, atomic mass, chemical families (groups), and
periods;
Instructional Objective(s)
Students will know that:
1. An atom’s identity is directly related to the number of protons in its nucleus. This is
the basis for the arrangement of atoms on the periodic table of elements.
2. The number of neutrons is found by the formula: Atomic Mass = Protons +
Neutrons
3. Protons and neutrons are found in the nucleus, while electrons are found in shells
outside the nucleus.
Students will understand that:
1. The periodic table of elements is a tool used to organize information about the
elements. Each box in the periodic table contains information about the structure of an
element.
Students will be able to:
1.
Use the periodic table to obtain the following information about the atom of an
element:
-
symbol
-
atomic number
-
number of protons, electrons and neutrons
-
atomic mass
-
number of outer energy level (valence) electrons.
-
state of matter at room temperature
2.
Create a 2D and 3D model of an atom
Engage
The students will be shown a claymation movie that shows how you can use the periodic
table to determine how many protons, neutrons, and electrons there are in that atom. After
knowing this information you can then create a 2D or 3D model to show what the atom
looks like. Although this is the whole lesson put into a video, the movie is short so the
students will not be able to process all of that information so quickly. It will give the students
a fun idea as to what they will be learning.
Explore
The students will be given example Bohr models and the periodic table square that match
that bohr model (The worksheet is attached). The students will use what they are given in
order to figure out how the square can be used to determine the number of protons,
neutrons and electrons. The students will work alone first and will then get with a partner or
a group of three to compare their findings. The students must write down on the worksheet
how they think the Bohr Models and the periodic table squares are related.
Attachments
Bohr_Model_vs_Table.doc
Explain
The students will explain to the class what they found about the relationship between the
Bohr models and the periodic table squares. The first thing to discuss is what the P stands
for, and how you know how many P's you have. The P stands for the number of protons,
which you know because they are found in the nucleus. The protons are found by looking at
the number above the symbol of the element. This number is known as the atomic number,
which is the basis for the arrangement of the periodic table. The atomic number for each
element tells you how many protons there are in the nucleus of the atom.
The next step is to talk about the electrons, which are found on the outside of the nucleus.
The number of electrons can be determined by the atomic number as well. It must be
pointed out however, that this only works for a neutral atom. An ion is an atom that has
either more protons than electrons (positive ion) or an atom that had more electrons than
protons (negative ion). The students could be able to guess what type of ion each would be.
So, the atomic number will tell you the number of protons and electrons when you are
talking about the neutral atom, which is what will be used in this lesson. In some periodic
tables, like the one I took the squares from, will tell you how many of these electrons will be
in each of the outer orbits. The first shell will always hold at least two; the second shell can
hold at least 8; the third shell can hold at least 18, etc.
The last step is to talk about the neutrons. This will be the hardest thing for the students to
determine, unless they have already learned it or remembered it from the claymation. The
teacher will take the ideas of the students and put them all together to allow the students to
determine that the neutrons involve both the atomic mass and the atomic number. The
neutrons are found by taking the atomic mass and subtracting the atomic number. Thi is the
number of neutrons, which is labeled N in the picture because they are found in the nucleus
with the protons. This then shows that the atomic mass is the number of protons + the
number of neutrons.
This will show how you use the periodic table to determine the make-up of the atom.
The teacher will have a SmartBoard set up so the students can create their own Bohr Model.
The teacher will give the class a periodic table square. The students will be able to come up
to the board, select the protons, neutrons or electrons and drag them to where they are
supposed to be. The students will be working together as a class to decide how many of
each part you need and where each of them should go.
Extend
If you look at an atom in 3D, how does it look?
The students will start researching an element of their choice. The students will be given
time to research their element in class. They will need to research about the characteristics
of the element and research its atomic structure. The students will be using computers to
research their element.
The students will be asked to create a 2D diagram of their element, but also to create a 3D
model of their element. This will allow the students to put the atomic structure into a bigger
picture by taking a look at it in 3D instead of 2D. Atoms are extremely small particles, so
creating a 3D model will give the students a better idea about what these atoms really look
like.
Evaluate
The students will be completing their project to create a 3D atomic model of an element.
The students will research the atomic make up of the element and will have to create a way
to build this 3D project. The students must include the name, symbol, group, period, number
of protons, number of neutrons, number of electrons, correct electron placement in energy
levels, characteristics about the element and the history of the element. The students will be
given class time this day, but will be expected to finish the project at home. There will be
checkpoints along the way to make sur that the students are keeping up on their work. The
students will have a week and a half to complete this project so they have 2 full weekends
to work on it. The project will be graded using a rubric.
Attachments
3D_atom_project.doc
Plans for Diversity
The students that are ready to handle a more difficult element will be able to choose
something that includes more creativity. It is hard to come up with a way to make a 3D atom
that could in over 100 protons and neutrons inside the nucleus. These students will have to
come up with creative ways to use things from home to create their 3D project. Those
students that may need a little bit more help, they can be given an element that may not
have as many parts to consider when creating the 3D diagram. I also don't want the
students spending a lot of money, so I want everyone to be able to use items that they have
in their home.
Connections
This lesson is important because it shows how the periodic table can be used to determine
atomic structure. This is helpful because it allows students to visualize what an atom looks
like. Visualizing the atom and seeing what the outer orbital looks like will help the students
get a better understanding of what happens during bonding. The outermost layer of
electrons is the most important part, which will be discussed in a later lesson. The electrons
are also important in other things such as electricity. Instead of just talking about electrons
it is essential to teach the entire atomic structure.