Flashcards in 1.6 bonding Deck (18):
1a How do we know that ions exist?
physical properties of ionic compounds (brittle)
electron density maps
1b How are ions formed?
electron loss or gain
1d What is an ionic crystal on a molecular level?
a giant lattice of alternating ions
1e What is an ionic bond?
electrostatic attraction between oppositely-charged ions
1f Define 'isoelectronic'.
same electronic structure
1f What is the trend in ionic radii of isoelectronic ions?
(eg N3- O2- F- Na+ Mg2+ Al3+)
decreasing radius as nuclear charge increases (thereby pulling electrons in closer)
1g How does an ionic lattice form?
metal loses electrons
non-metal gains electrons
ions are attracted to one another
1i What is polarisation (of ions)?
electron imbalance from attraction to other nuclei, causing one end to be more negative than another
1j Which two factors increase the polarising power of a cation?
radius (smaller radius, more polarising)
nuclear charge (greater charge, more polarising)
1j Which factor increases the polarising power of an anion?
radius (larger radius, more polarisable)
1k What does polarisation within ionic compounds lead to?
covalency (more polarised compounds are more covalent)
1l How does the enthalpy of formation of MgCl2 prove that it is more stable than MgCl or MgCl3?
[waiting on answer from nmb]
2a How is a covalent bond formed?
attraction between nuclei and shared pair(s) of electrons inbetween
2ai How can we tell that covalent bonds are strong?
giant covalent structures (e.g. diamond) have high sublimation points
2aii How do electron density maps prove the strength of covalent bonds?
buildup of electrons between nuclei - attraction
2b What is a dative covalent bond?
a covalent bond wherein both of the electrons inbetween came from the same electron
3a What do metals look like on a molecular level?
giant lattices of metal ions and delocalised electrons