1.4.1 describe the different building blocks of matter.
Particulate nature of matter: atoms, molecules and ions.
NOTE
Diagrammatic representation is necessary for atoms and molecules of the 1st to 18th elements of the periodic table
Draw and label the following atoms: Oxygen, Hydrogen and Chlorine
1.4.2 differentiate between elements, compounds and mixtures.
Discuss and bring out the differences between elements, compounds and mixtures.
Classify the following materials into elements, compounds and mixtures: water, salt, iron filings sea water, Sulphur, air and glass.
1.4.3 describe the formation of covalent and ionic compounds.
Use models or diagrams to assist the students to discuss:
1. Ionic bond formation as a result of transfer of electrons from one atom to another resulting in the formation of cations and anions.
2. Electrostatic attractions between cations and anion to give ionic bond.
3. Covalent bond formation between atoms or groups to give covalent compound
4. characteristic properties of ionic and covalent compounds
NOTE:
IUPAC names of common compounds should be taught.
discuss the items listed under the content.
Describe the formation of sodium chloride (NaCl) and ammonia (NH3)
1.4.4 relate atomic numbers, mass numbers, isotopes and relative atomic mass among each other.
Write down mass number of a given element based on given number of protons or electrons and number of neutrons.
Explain relative atomic masses using the periodic table.
NOTE:
Carbon-12 isotope should be mentioned as the reference scale.
Explain the term isotopes and give three examples of elements that exhibit isotopy.
1.4.5 perform calculations using the mole concept.
Mole, molar mass and formula mass.
Relationship between grams and moles
calculate the following:
1. Formula mass and molar mass using given relative atomic masses.
2. Amount of substance in moles given its mass
NOTE: Mention should be made of the mole as a unit of the physical quantity, amount of substance.
L = 6.02 x 1023 particles as the Avogadro constant;
use of n = m/M relationship to calculate amount of substance where n is the symbol for amount of substance, m is the mass, M is the molar mass.
Calculate the amount of substance in 9g of aluminum
(Al = 27 g/mol)
1.4.6 prepare solutions of given concentrations.
Brainstorm to define the concentration of a solution in units of moldm-3; gdm -3 ; part per million (ppm) and percentage.
carry out simple calculations with the relationship
Prepare solutions of a given concentration e.g. IM solution of
(a) NaOH
(b) NaCl (c) sugar
Dilute solutions of given concentrations and discuss everyday application of dilution e.g. food preparation, drug preparation.
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