3/13/2013 (Unit 5) LEQ: What Types of Elements Are on the Periodic Table?

3/13/2013 (Unit 5) LEQ: What types of elements are on the periodic table?

On the periodic table:

Rows are called periods * All elements in a period have the same highest energy level

Columns are called groups or families * The most common method of identifying columns in numbering them from 1-18 * Sometimes a family is named by its top element * Elements in a family have very similar characteristics because they all have the same electron configuration ending. Electrons affect properties.

Types of elements we see on the periodic table:

Alkali Metals – Group 1 * Soft solids – can be cut with a spade * Highly reactive, especially with water (only need to lose 1 electron) - since they are so reactive, they’re not typically found as the pure element in nature, but rather bonded in a compound * Have one valence electron * Doesn’t include Hydrogen

Alkaline Earth Metals – Group 2 * Harder than Alkali Metals * 2 valence electrons * Generally combine with non-metals to make compounds

Transition Metals – Groups 3-12 * Good conductors of heat and electricity * Typically malleable and shiny * Much less reactive than groups 1 and 2, often found in nature as pure element * Lose electrons in reactions, becoming cations * The easier an element loses electrons, the more metallic it is

Post-Transition Metals- found between Transition Metals and Metalloids * Show many of the same characteristics as Transition Metals

Metalloids (or semi-metals) * Brittle solids with properties of both metals and non-metals * The “tweeners” between metals and non-metals * Show not as much conductivity as metals but more than non-metals, so they are sometimes described as being semi-conductive.

Other Non-Metals * Mixed group of elements that don’t really fit anywhere else * Include hydrogen * Made up of both solids and gases * Don’t have a defining characteristic for the group Halogens – Group 17 * Most reactive group of the non-metals (b/c only need to gain 1 electron) * Typically will gain one electron in reactions to achieve an octet * Contain all 3 states of matter (solid, liquid, gas)

Noble Gases – Group 18 * Inert gases (meaning they don’t react very often) because they already have an octet

Inner Transition Metals – Traditionally below the main periodic table * Actually belong between the Alkaline Earth Metals and Transition Metals * Made up of two different periods, called series:

Lanthanide Series (Lanthanoids) * Shiny metals * Similar reactivity to Alkaline Earth Metals

Actinide Series (Actinoids) * Metals that tend to be radioactive * Only the first 4 elements are natural, the rest are synthetic (man- made)