This activity can help you introduce atomic structure to students who have no prior experience with this subject. Ask six students to each make one yellow 3-inch diameter circle out of construction paper, another six students to create red 3-inch diameter circles and a third six-student group to form blue 3-inch diameter circles. Ask each student to hold his own circle high. Use chalk to draw a ring on the floor and ask "blue" and "yellow" students to enter the ring. Then, ask two "red" students to stand one step away from the ring and the four remaining "reds" to stand two steps away from the ring. Explain to students that they have formed a human carbon atom, with those in the ring representing the protons and neutrons -- and collectively the nucleus -- and those outside being the electrons, divided into two energy levels.
Give students the number of atoms, protons and electrons within a chemical element's atom. In addition, inform them about the number of energy levels the atom has and the number of electrons on each level. Ask students to make clay balls to depict the subatomic articles, using a different clay color for protons, neutrons and electrons. Students must also draw concentric circles of varying diameters in their notebook, depicting the different energy levels, and place the electrons on them, according to your instructions. For the nucleus, children must squeeze the proton and neutron balls together -- gently so they don't lose their shape -- and place them on the inner circle of the drawing.
Write the atomic symbol of an element, such as that of calcium (Ca) on the board. Write the mass number of calcium, 40, on the top-left side of the symbol and the atomic number on the bottom-left side. Explain to students that the mass number shows the number of protons and neutrons put together, while the atomic number shows only the number of protons and electrons on an atom with a neutral charge. Afterward, write incomplete atomic symbols of several elements, and ask students to find the missing numbers. For example, ask for the mass number of copper, which has an atomic number of 29 and 35 neutrons, or the atomic number of palladium, which has an mass number of 106 and 60 neutrons.
Bring a large poster of the periodic table into the classroom. Explain to students that the numbers over every chemical symbol denote the number of protons in the element's atom. For example, hydrogen only has one proton, while nickel has 28. Prepare a number of atomic structure representations on flashcards, which also signify the number of protons and neutrons in the atom's nucleus. Show one flashcard at a time to students and ask them to use the number of protons as a guide to navigate around the periodic table and name the element.