AQA A-Level Chemistry – Bonding Practice Questions .

AQA A-Level Chemistry – Bonding Practice Questions .Ionic Bonding - ANSWER A bond between metals and non-metals. The metal will donate electrons to the non-metal in order to achieve a full outer shell and achieving noble gas status. This allows the molecules to be ionised, forming attraction towards one another due to opposite charge attraction via electrostatic forces Ionic Lattice - ANSWER The structure of an ionic compound. This allows the compound to be brittle and non-conductive in a solid state Covalent Bonding - ANSWER A bond between non-metals. The non-metals will share an electron each to form a single bond (or 2 for double and 3 for triple bonds). This can be maintained due to electrostatic forces maintaining their electron clouds Co-ordinate Bonding - ANSWER A bond by which a lone pair of electrons shares its pair with an atom that is electron deficient. This is a type of covalent bond, also known as dative covalent bonding Metallic Bonding - ANSWER A bond between metals. Consists of positive nuclei dispersed in a sea of delocalised electrons. Allowing the metal to be conducting at a solid state. This sea also allows the metal to be malleable and ductile Electronegativity - ANSWER The power of an atom to attract its electron density towards itself in a covalent bond N, O, F - ANSWER The only elements that create hydrogen bonds due to their high electronegativity Factors Affecting Electronegativity - ANSWER Affected by; - shielding (more = less electronegativity) - the nuclear charge (more = more electronegativity) - atomic radius (smaller = more electronegativity) Trend in Electronegativity - ANSWER Increases across a period and increases up a group Intermolecular Forces - ANSWER van der Waals, dipole-dipole and hydrogen bonding van der Waals - ANSWER The mimicking of electron clouds due to the constant changing of electron clouds, forming an instantaneous dipole. This occurs between all molecules at all times Dipole-Dipole - ANSWER The rotation of molecules due to molecules with a constant biased electron cloud. This causes like partial charge repulsion and opposite partial charge attraction. This only occurs between molecules with permanent biased electron clouds Permanent Dipole - ANSWER Biased electron cloud, represented by a lower-case delta Hydrogen Bonding - ANSWER A highly electronegative element will be bonded to hydrogen. This induces a biased electron cloud, giving the hydrogen a partially positive charge. This hydrogen then has opposite charge attraction between its partial positive charge and lone pairs on other molecules. This only occurs if the hydrogen is bonded to N, O or F. Note: this is why oxygen has a high surface tension