Students use the APH atom model to both become familiar with the concept of atomic number and mass number and to display (model) their understanding of these concepts. These concepts are much clearer and more concrete for students who are blind or visually impaired when taught with a model. I find the APH model to be an excellent resource. The atom model is part of the Azer Periodic Table Set and can also be purchased separately
After initial instruction on the structure of the atom and the use of the AZER atom model, set up a different atom for each member of the class using the APH atom model. See picture above
If you are not familiar with this model, it is available using quota funds through APH. Many Region Service Center here in Texas already own a set or more. I usually start with the “early” atoms from the Periodic Table; Hydrogen, Helium, Lithium, Beryllium, and Boron so that the atomic number and mass number will be easy to count.
Define related terms:
Have students switch atoms with another student and repeat the activity. Have students check each others calculations and discuss.
Once students are comfortable with the concepts of atomic mass and mass number, have students calculate the following:
They will accomplish this task using only subtraction.
Mass number – atomic number (number of protons) = number of neutrons
Mass number – number of neutrons = atomic number (# of protons)
High School: Structure and Properties of Matter
PS1.A: Structure and Properties of Matter
Each atom has a charged substructure consisting of a nucleus, which is made of protons and neutrons, surrounded by electrons. (HS-PS1-1) The periodic table orders elements horizontally by the number of protons in the atom’s nucleus and places those with similar chemical properties in columns. The repeating patterns of this table reflect patterns of outer electron states. (HS-PS1-1)
By Laura Hospitál
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