P. Sci. Unit 8 Periodic Table Chapter 5. Periodic Law Properties of elements tend to change in a regular pattern when elements are arranged in order of.

P. Sci.

Unit 8Periodic TableChapter 5

Periodic Law

• Properties of elements tend to change in a regular pattern when elements are arranged in order of increasing atomic number, or number of protons in their atoms.

Periodic TableThe periodic table is arranged in-

• Periods (horizontal) rows

–There are 7 periods

• Groups families (vertical) columns–There are 18 columns

Metals• all elements on the left side of the

table (except Hydrogen)

Non - Metals• all elements on the right side of

the table

Hydrogen• Hydrogen (1) – 90% of the atoms

in the universe – (diatomic – two atoms of the same element in a covalent bond – H,N,O,F,Cl,Br,I). Very reactive, both covalent and ionic bonds can form

Metalloids• elements that share both

metal and non-metal characteristics – the elements on both sides of the stair-step line except aluminum.

• Also called semiconductors

Alkali Metals• (Column 1 except

Hydrogen) – the most reactive group – do not occur in nature in their elemental form. Has one electron in its outer energy level

• All (including hydrogen) have 1 valence electron.

Hhydrogen

Alkaline Earth Metals

• (Column 2) – also reactive – also do not occur in nature alone (fireworks)

• 2 valence electrons.

Li

Na

K

Rb

Transition Elements

• (Columns 3 – 12) stable metals – occur in natural state.

• usually have 2 – 3 valence electrons to give up to form bonds.

Mixed groups

• Boron group (13) – mixed with both metals and non-metals.

• 3 valence electrons

Mixed groups cont.• Carbon group (14) –

mixed with both metals and non-metals.

• 4 valence electrons

Mixed groups cont.• Nitrogen group (15)

– mixed – tend to share to form covalent bonds – fertilizers.

• 5 valence electrons

Mixed groups cont.

• Oxygen group (16) – mixed

• 6 Valence electrons

Halogens• (17 – all nonmetal) –

very reactive in their element form. If combined with a metal forms salt. Many are diatomic (F,Cl,Br) Br – only nonmetal liquid.

• 7 valence electrons

Noble Gases• (18)– Most stable because outer

layer is full. No known natural compounds. Helium gas, neon / argon in neon lights, argon / krypton in electric light-bulbs, used to produce lasers

• 8 valence electrons (full shell)

Other Groups

• Iron Triad – Iron, Cobalt, and Nickel – create steel and other metal mixtures.

Other groups cont.

• Coinage group – Copper, Silver, and Gold – stable and malleable and found in nature – used to make coins.

Other groups cont.

• Coating metals / Zinc group – Zinc, Cadmium, and Mercury – used to coat or plate other metals – Mercury only liquid metal (cadmium and mercury used in batteries.)

Other groups cont.

• Lanthanide series –

elements 58 – 71

• Actinide series –

elements 90 – 103

• Transuranium –

all elements over 92

Allotropes• (recall isotopes) – materials

made of the same element that have different molecular structure.

Diamonds

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