Covalent Bonding PDF
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This document covers the topic of covalent bonding in chemistry. It describes how covalent bonds form, the properties of covalent compounds, and provides examples like water and methane using dot and cross diagrams. It also touches upon the periodic table and allotropes of carbon.
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Covalent bonding Learning outcome Describe how covalent bonds form Understand how to draw the dot and cross model State the properties of covalent bonds Covalent bonding Occurs between non-metal atoms The atoms share electrons The shared pair of electrons holds the atoms tog...
Covalent bonding Learning outcome Describe how covalent bonds form Understand how to draw the dot and cross model State the properties of covalent bonds Covalent bonding Occurs between non-metal atoms The atoms share electrons The shared pair of electrons holds the atoms together There are no free electrons or ions so the compounds cannot conduct electricity Examples Properties Covalent compounds are gases or liquids Low melting points Do not conduct electricity How covalent bonds form: dot and cross model Carbon 1. C has 4 electrons in outer shell C needs 4 more electrons to be stable O has 6 electrons in Oxygen outer shell O needs 2 more electrons to be stable Oxygen and carbon dioxide electrons are shared full circles should be drawn Only outer shells have been drawn Intermolecular bonds The covalent bonds binding the atoms together are very strong but there are only very weak forces holding the molecules to each other (the intermolecular forces). Intermolecular bonds Therefore, only a low temperature is needed to separate the molecules when they're melted or boiled. The periodic table Columns in the periodic table Columns are called groups Elements in the same group have similar chemical properties The group number = the number of electrons in the outer shell eg Group 1 have 1 electron in outer shell Rows in the periodic table Rows = periods The period number is the same as the number of electron shells that are occupied Allotropes of carbon Allotrope: different structural form of an element Carbon forms 3 different different: diamond, graphite and fullerene Each allotrope has a different property The atoms are joined by strong covalent bonds Graphite Formed in layers Black, shiny and opaque Conducts electricity because there are free electrons Diamond 1 Lustrous (shiny) 2(transparent) Colourless and clear 3 Hard 4 High melting point 5dissolve) Insoluble in water (does not 6 Does not conduct electricity Fullerenes Contains 60 carbon atoms in the structure of a ball
