9781422279496

Elements play a part in everything in this photo, from clothes to leaves to people!

has undergone several updates and reorganizations since it was first developed in 1869. In the modern version of the table used today, it is arranged by increasing atomic number, into rows and columns. Each element has a unique atomic number. It is the number of protons in the nucleus of the atom. For example, uranium has an atomic number of 92—there are 92 protons in the nucleus. Hydrogen, on the other hand, has only one. 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. Certain chemical properties can be interpreted based on which group or row an element resides in. Each

The Chemistry of Everyday Elements

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