9781422279489

ing 26 (and counting) have been manufactured and analyzed in a laboratory setting. These ele- ments, alone or in combination with others, form and shape all the matter around us. From the air we breathe, to the water we drink, to the food we eat—all these things are made of elements. We can learn a lot about an element just by finding its location on the periodic table. The periodic table has undergone several updates and reorganizations since it was first developed in 1869, until it be- came the modern version of the table used today. The periodic table is arranged into rows and columns by increasing atomic number. Each element has a unique atomic number. It is the number of protons in the nucleus of the atom. (All samples of an element have the same number of protons, but they may have a different number of neutrons in the nucleus. Atoms with the same number of protons but different number of neutrons are called isotopes .) Each element on the periodic table is unique, having its own chemical and physical properties. Certain chemical properties can be Don’t hold your breath too long! We can’t live without oxygen from the air.

The Chemistry of Everyday Elements

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