CHM 1142 Lecture 7: Chapter 7 - Periodic Properties of the Elements
Document Summary
Dmitri mendeleev and lothar meyer independently came to the same conclusion about the elements and how they should be grouped. Chemists mostly credit mendeleev because he also used chemical properties to organize the table and predicted some missing elements and their expected properties. It was the most fundamental property of element known at the time. About 35 years later, the nuclear atom was discovered by rutherford. Henry mosley developed the concept of atomic number experimentally. The number of protons was considered the basis for the periodic property of elements. Repetitive pattern of a property for elements based on atomic number. The following properties are discussed in this chapter: Electrons are both attracted to the nucleus and repelled by other electrons. The effective nuclear charge {zeff} is found: zeff = z-s. Where z is the atomic number and s is a screening constant usually close to the number of inner electrons. Usually increases across a period and decreases down a group.
