What properties did Mendeleyev use to sort the elements in his table?
atomic weight, chemical "additive" power (as in the combining with oxygen)
thank you
To sort the elements in his table, Dmitri Mendeleev used several properties of the elements. Here are the key properties he considered:
1. Atomic Mass: Mendeleev arranged the elements in increasing order of atomic mass. He recognized that the properties of elements tended to recur at regular intervals when arranged in this manner.
2. Chemical Similarities: Mendeleev also took into account the chemical similarities between elements. He noticed that elements with similar chemical properties tended to have similar atomic masses. By organizing elements with similar properties into vertical columns (groups/families), he created a systematic arrangement for the periodic table.
3. Valence Electrons: Mendeleev assigned each element a "valence" or "combining power," which referred to the number of electrons in the outermost energy level. He found that elements with similar valence electron configurations exhibited similar chemical behavior. This influenced the placement of elements in the same groups.
4. Periodicity: Mendeleev observed that certain properties of elements repeated periodically. For example, every eighth element (starting from lithium) displayed similar chemical behavior. This periodicity in properties led to the concept of periods (horizontal rows) in the periodic table.
By considering these properties and arranging the elements in a systematic manner, Mendeleev was able to create the first version of the periodic table, which laid the foundation for our modern understanding of the elements.