Language of Chemistry - Variable Valency, Radicals, & Chemical Formula

Extract

[...] 3 Tetravalent Radicals (Valency = Radical Valency 4 7. CHEMICAL FORMULA Definition A chemical formula is the symbolic representation of a molecule of an element or compound. Importance of a Chemical Formula A chemical formula tells us: 1. The name of the compound. 2. The elements present in the compound. 3. The number of atoms of each element present. Example 1 NaCl Na = Sodium Cl = Chlorine The compound is Sodium Chloride. Example 2 H?SO? Hydrogen = 2 atoms Sulphur = 1 atom Oxygen = 4 atoms The compound is Sulphuric Acid. [...]

[...] Example 3 - Mercury Oxide Step 1 Hg² O² Step 2 Divide by common factor 2 Hg¹ O¹ Step 3 Interchange Hg?O? Step 4 Ignore 1 Final Formula = HgO QUICK REVISION Learn These Definitions Variable Valency - Ability of an element to show more than one valency. Radical - An atom or group of atoms carrying a charge and acting as a single unit. Chemical Formula - Symbolic representation of a molecule. Cation - Positively charged radical. Anion - Negatively charged radical. Remember - Positive radical ? Left side - Negative radical ? [...]

[...] Language of Chemistry - Variable Valency, Radicals, & Chemical Formula CHEMISTRY SESSION 2 NOTES CHAPTER: LANGUAGE OF CHEMSITRY TOPIC : VARIABLE VALENCY, RADICALS, & CHEMICAL FORMULA 1. VARIABLE VALENCY Definition Most elements have a fixed valency. However, some elements can show more than one valency. Such elements are said to have Variable Valency. Example: Iron Iron combines with chlorine in two different ways. FeCl? Iron combines with 2 chlorine atoms. Valency of Iron = 2 FeCl? Iron combines with 3 chlorine atoms. [...]

[...] Sodium Potassium Ca²? Calcium Mg²? Magnesium Cl? Chloride Br? Bromide B. Compound Radicals A radical consisting of two or more atoms. Examples Radical Name Ammonium OH? Hydroxide SO?²? Sulphate CO?²? Carbonate Nitrate 5. POSITIVE AND NEGATIVE RADICALS Positive Radicals (Cations) Radicals carrying a positive charge are called cations. Examples: Na? Ca²? Mg²? Negative Radicals (Anions) Radicals carrying a negative charge are called anions. Examples: Cl? OH? SO?²? CO?²? 6. VALENCY OF COMMON RADICALS Monovalent Radicals (Valency = Radical Valency 1 Na? [...]