Chemistry grade 10
Dec 23, 2015
Chemistry grade 10
Electron arrangement
Chemical compounds are represented using chemical names and chemical formulas.
• To tell different compounds apart, each one is given a unique chemical name.
• Each chemical name can be translated into a chemical formula. A chemical formula is a group
of letters and subscript numbers that represent the make-up of a chemical compound.
The letters in the compound are the chemical symbols of the elements in the compound.
• The subscript numbers tell you how many atoms of these elements are in the compound.
• Reactive elements can become more stable when they form compounds.
Sodium + Chlorine becomes sodium chloride
Compounds
• When elements form compounds, they become more stable because when the elements combine to form compounds, each element makes a full outer electron shell.
• Metal elements lose electrons to form positive ions to become more stable.
• Non-metal elements can gain electrons to form negative ions OR non-metals can share electrons to become more stable.
• Ions are atoms that have either a positive electrical charge or a negative electrical charge.
Binary Ionic compound
• A compound consists of a metal cation and non-metal anion.
• First part of the name always identifies the cation – usually a metal
• Second part of the name identifies the anion. Ends in the suffix “ide”
Name Symbol
Fluoride F-
Chloride Cl-
Oxide O2-
Sulfide S2-
Nitride N3-
Phosphide P3-
Elements in Ionic compound Name of Ionic compoundMagnesium and phosphorus Magnesium phosphideSodium and chlorine Sodium chlorideCalcium and bromine Calcium bromideAluminum and oxygen Aluminum oxide