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”

NameSymbol FluorideF-F- ChlorideCl - OxideO 2- SulfideS 2- NitrideN 3- PhosphideP 3-

Elements in Ionic compoundName of Ionic compound Magnesium and phosphorusMagnesium phosphide Sodium and chlorineSodium chloride Calcium and bromineCalcium bromide Aluminum and oxygenAluminum oxide