Eighth-Grade Science Is Elemental


This year, Rim Country Middle School eighth-graders studied the periodic table of the elements with models in hand.

The models and other scientific materials in use in Barbara Toma's and Barbara Quinlan's classes were obtained through a grant from the Payson Rotary Club earlier this year.


As eighth-graders, (left to right) Brandon Christensen, Daniel Conley, Blake Brown, Dillon Buchanen (front) begin to learn the mystery of the atom.

"Labs are the best part of science," students Justin Moratti and Clayton Duhamell agreed.

The density bottles and sink tubes used for this lab that helped Quinlan and Toma explain the Scientific Method to their pupils were also purchased with the grant money.

Science is a year-long required course for the eighth-graders and the teaching aids help hold their interest. They also help many student understand confusing concepts like ions and isotopes.

Having a model to hold in your hands will help you determine the difference between ions and isotopes and how they are written, Quinlan told her pupils.

The periodic table of the elements was created by Dimitri Mendeleyev, a Russian scientist in the 1920s. He sought to organize the scattered lists of elements and discovered that the elements' properties recur in a periodic manner based on their atomic weight.

At that time there were only 63 elements known to science. So, he made gaps and predictions where he thought new elements might be found.

There are currently 129 elements listed on the periodic table, including 92 that occur naturally.

Element 101, mendelevium, was named after Mendeleyev. It is a synthetic element.

The table the eighth-graders were given lists the atomic number, the symbol and the name.

The atomic number is the number of electrons a particular element has.

For instance, zinc has 30 protons. Its symbol is: Zn.

The pre-lab questions included the number of neutrons and electrons of a particular element.

Zinc has 36 neutrons and 36 electrons.

Atoms of the same element that have the same number of protons and electrons but a different number of neutrons have an isotope name.

To write the isotope name for an element the mass, or what is in an atom's nucleus, must first be calculated by adding the number of protons and neutron together.

Zinc mass is 66. Its isotope is properly written as: Zinc - 66.

An ion is an element that has lost or gained electrons, Quinlan wrote on the board.

Pre-filled clear bags marked with the number of electrons on the outside and black marbles for protons and blue for neutrons inside were passed around from lab partner to lab partner.

"Think of these bags as the nucleus of an atom," Quinlan told her pupils.

Students broke the elements down further in the lab creating a data table that included the mane of the element, symbol, its mass, number of protons, neutrons, electrons, ion symbol and isotope symbol.

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