chem classificationsofmatter

Structure 3.1.1 - the periodic table consists of periods, groups and blocks

see 3.1.4 periodicity in reactivity
see 3.1.3 periodicity in properties of elements
see 3.1.2 periodicity and electron configuration

the periodic law states that after certain regular but varying intervals, the chemical elements show an approximate repetition in their properties.

elements are placed in order of increasing atomic number (), the number of protons in the nucleus of its atoms

the columns of the table are called groups and the rows are called periods

metallic elements are found in the sblock, in the central d block, and in the island of the f block. a small number of metals are found on the left of the p block

the non-metals are found on the upper right-hand side of the p block

the metalloid elements have the characteristics of both metals and non-metals. their physical properties and appearance most resemble the metals, although chemically they have more in common with the non-metals

challenge questions
  1. four elements derive their name from a small town called Ytterby, just outside Stockholm, Sweden. try to find their names

ytterbium, yttrium, terbium, erbium

  1. state the electron configuration of europium

  1. how many elements in the periodic table are liquids and how many are gases?

2 liquids, 10 gases

  1. distinguish between the terms “metalloid” and “semiconductor”.

metalloid refers to the properties of elements in the periodic table. semiconductor refers to the physical properties of materials. there is some overlap between the two.