Unit 2
No description yet. This curated deck is ready for daily study.
Card preview (13)
How do you calculate relative atomic mass for isotopes?
Times the mass and percentage of isotopes together add the resultsand divide by 100.
What is a positive ion called?
Cation
What is a negative ion called?
Anion
What is an ionic bond?
A strong electrostatic attraction between oppositely charged ions.
Describe the structure of ionic compounds:
Giant lattice of ionic compounds as a regular arrangement of alternating positive and negative ions.
What type of elements do ionic bonds occur between?
Metallic and non metallic
2 properties of ionic compounds:
• High melting and boiling points • Good electrical conductivity when aqueous or molten - poor when solid. (so charges/ions can flow freely)
What is a covalent bond?
A covalent bond is formed when a pair of electrons is shared between two atoms leading to noble gas electroninc configurations
2 properties of covalent bonded compounds:
• Low melting and boilings points - weak intermolecular forces • Poor electrical conductivity
2 giant covalent structures?
• Diamond - cutting tools • Graphite - lubricant and electrode
What is the structure of silicon (IV) oxide? SiO2
Each oxygen atom forms covalent bonds with 2 silicon atoms and each silicon atom in turn forms covalent bonds with 4 oxygen atoms. Tetrahedron
What is metallic bonding?
The bonding from electrostatic attraction between the positive ions in a giant metallic lattice and a ‘sea’ of delocalised electrons
2 Physical Properties of metallic bonded substances:
• Good electrical conductivity • Malleability and ductility