Bonding (S2) Flashcards
(21 cards)
How to name ionic compounds?
first name of cation, then anion with ,,-ide” ending, e.g. potassium iodide
What is a lattice?
the arrangement of atoms that represents the structure of crystals
What is ionic bond?
bond between two atoms formed by transfer of electrons between them
What is the melting point of ionic substances?
very high
What affects the strength of ionic bonds?
- higher charge = greater strength
- distance between the centres (larger atoms = worse strength)
What is lattice enthalpy?
energy required to break ionic bond to form gaseous ions
Comment on electrical conductivity of ionic substances
- electrical conductivity requires mobile charges
- solid is too locked to conduct
- liquid allows for free movement of ions so it’s a good conductor
Are ionic substances soluble in water? Why?
yes, because water molecules have negative and positive regions, which are attracted to positively or negatively charged ions
What’s the properties of ionic substances?
- good conductors in liquid state
- soluble in water
- brittle
- not volatile
Why solid ionic substances are brittle?
because force, cause them to slightly move, and then ions with the same charge are next to each other and repel
What is votility?
ease of evaporation
What is a covalent bond?
attraction between shared pair of electrons and positively charged nucleus
What are the valence electrons?
electrons in the highest energy level, e.g. 1, 2, 3, 4 etc.
What is an octet rule?
tendency of atoms to have a valence shell with 8 electrons
How to find a lewis structure?
- calculate total number of valence electrons
- draw skeletal structure
- complete the octet of the atoms with remaining electron pairs
- if any electron pair remains, give it to central atom
- if central atom doesn’t have octet, then move pairs to create double or triple bonds
Which elements do not follow an octet rule?
Be (stable with 4) and B (stable with 6)
What is bond length?
distance between two nuclei
What is bond strength?
energy to break one mole of bonds
What is a coordination bond?
covalent bond in which both shared electrons come from the same atom
