شرح درس
Chemical Equation
CHEMISTRY - Secondary 1
In This part we will study
Symbolic chemical equation: A group of chemical symbols and formulas of the reactants and products which are connected by an arrow that expresses the direction of this reaction and carries its conditions.
The following table represents signs which are included in any chemical equation and their indications:
In the lower right-hand corner of the element symbol or the chemical formula, certain symbols are written to indicate the different physical states of each reactant and product
illustrated in the following table :
Symbol (s) (L) (g) (aq) (v)
Indicated
physical state solid liquid gas Aqueous
solution vapour
(solid or liquid vapourized
by heat)
Examples Mg(s)
NaCl(s) H2O(L)
Br2(L) O2(g)
CO2(g) H2SO4(aq)
NaCl(aq) Br2(v)
H2O(v)

On the arrow which determines the reaction direction, reaction conditions are written (if there are conditions) , as those which are shown in the following table :
Balanced chemical equations
The balanced chemical equation represents the ratios of the definite amounts by which the reactants react together to form the products.
In the balanced equation it is considered that:
 Number of atoms of each element in the reactants equals the number of its atoms in the products to satisfy the law of conservation of matter.
This is fulfilled by writing numbers preceding the elements symbols and the chemical formulas of the compounds known as the coefficients, they represent the simplest ratio by which the reactants react together to form products.

Best wishes to you
Mr.Ahmed Elbasha

كيمياء الصف الاول الثانوي لغات - الفصل الدراسي الاول
شرح كيمياء لغات اولي ثانوي - مستر احمد الباشا
كيمياء لغات - الصف الاول الثانوي - كيمياء اولي ثانوي الترم الاول - كيمستري اولي ثانوي الترم الاول