What is a molecular formula (MF)?
actual formula of the atom/ioneg: H2, N2
When is a covalent bond formed?
- when atoms of non-metallic elements share electrons to form molecules - achieve the stable electronic configuration of a noble gas
What do non-metallic elements share in their electrons to form covalent bonds?
The electrostatic FOA btw the 2 +vely charged nucleus and the pair of -vely charged electrons they share
What is Structural formula (SF)? What has SF?
- only for covalent bonds - how the 2 atoms are bonded - no. of lines in btw atoms = no. of covalent bonds - can be in any directioneg: H-H, O=O
Prefixes for names and chemical formulas of covalent molecules
1: mono2. Di3. Tri4. Tetra
Specific naming of some covalent molecules (1. Water 2. Ammonia 3. Methane)
1. Water H202. Ammonia NH33. Methane CH4
How are atoms bonded in simple molecular/covalent structure?
- within the molecules, atoms are bonded by strong covalent bonds- small molecules are held loosely together by weak intermolecular forces/weak Van der Waals' FOA
Physical properties of substances with simple covalent structure (mp and bp)
Low mp and bp, many are gases at room temp- simple covalent structure- consisting of discrete molecules- held together by weak Van der Waals' FOA- little amt of energy is required to overcome this FOA
Physical properties of substances with simple covalent structure (Electrical conductivity)
Unable to conduct electricity in all states- simple covalent structure- consisting of discrete molecules- held together by weak Van der Waals' FOA- molecules are electrically neutral- no mobile ions or electrons to conduct electricity
Answer keywords for physical properties of substances with simple covalent structure
1. Structure2. FOA3. particles4. Conclusion
Physical properties of substances with simple covalent structure (Solubility): just state main sentence, don't need to explain
Insoluble in water but soluble in organic solvents like petrol, ethanol