Chapter 5 - Periodic Trends

representative groups & properties

The elements of group 1 and group 2 and the elements from group 13 to group 18 of the periodic table are known as representative elements. Elements in which all the inner shells are complete but outer shell is incomplete is known as representative elements.

periodic trends

specific patterns that are present in the periodic table that illustrate different aspects of a certain element.

includes: electronegativity, ionization energy, electron affinity, atomic radius, melting point, and metallic character.

radius

the shortest distance between the atom's nuclei and the outermost shell of the atom.

ionic radius

the distance between the nucleus of an ion and the outermost shell of the ion

ionization energy

Energy required to remove an electron from an atom. measured in kilojoules (KJ)

electron affinity

the likelihood of an atom to gain an electron. Measured in Kilojoules (KJ)

electronegativity

Tendency to attract electrons to itself in a chemical bond. Scale from 0-4.0 (lowest to highest attraction)

activity of metals

activity of nonmetals

cations/charges on metal ions

cations are ions that are positively charged. they are smaller than the atoms from which they are formed

anions/charges on nonmetal ions

non-metal atoms gain electrons to form negatively charged ions.

octet rule

the tendency of atoms to prefer to have eight electrons in the valence shell. When atoms have fewer than eight electrons, they tend to react and form more stable compounds.

valence electrons

the electrons in the outermost shell, or energy level, of an atom

inert

An inert chemical substance is one that is not generally reactive.

bohr models

electrons orbit the nucleus at fixed energy levels