The periodic table is an organized array of all the chemical elements in order of increasing atomic number (the total number of protons in the atom's nucleus). When the elements are arranged, they reveal links and trends in their chemical properties.
In 1869, Russian chemist Dmitri Mendeleev noticed an innate pattern in the properties of some of the chemical elements. He began to develop the periodic table.
Initially, Mendeleev placed the 17 elements in vertical columns called groups. Periods were horizontal rows, and families were vertical columns of elements that shared similar properties.
Today, the periodic table has 118 elements. In addition to metals, it includes non-metals and rare earth elements.
Some of the more interesting and unusual elements are those that were discovered only recently, such as helium, neon, argon, and krypton. Others are important in everyday life, such as water, oxygen, and hydrogen.
As a part of the science curriculum, most school students will encounter some of the elements on the periodic table at some point. This quiz can help them remember some of the elements they may already know and can be used to spark discussion about these elements, their uses, and importance in the world around them.
1. Explain how the elements in the periodic table are grouped together.
2. Explain why the grouping of elements is done.
3. Remind students that the elements in the periodic table are arranged in groups, periods and families.