How many protons, neutrons, and electrons does one atom of calcium have?

Atoms can be broken down into three basic parts— protons, neutrons, and electrons. Using a few common household items, you can build three-dimensional models of different types of atoms.

• Label the sticker dots with symbols to represent the electrical charge. A plus symbol (+) represents a positive charge, a zero (0) is neutral, and a minus symbol (-) is a negative charge. • Select gumdrops to represent protons, neutrons, and electrons. Label each with the appropriate sticker dot. • Using the toothpicks, create a nucleus containing protons and neutrons for a lithium atom. You may need to break the toothpicks into pieces. Use the periodic table to figure out how many protons and neutrons are in a lithium atom. • Attach electrons to your lithium atom’s nucleus. Use the long wooden skewers. • What charge does the atom have? Why? If you remove one electron, what charge does it now have? Why? • Using the periodic table, select several other atoms, such as helium, carbon, and oxygen. Create models for these atoms.

To investigate more, try combining several atom models to create molecules. Ideas include water (H 2 O) and carbon dioxide (CO 2 ).

• small sticker dots • variety of different colored gumdrops • several wooden toothpicks • several long wooden skewers • periodic table (page 117) Ideas for Supplies