1.6 bonding Flashcards Preview

Chemistry AS (2015) > 1.6 bonding > Flashcards

Flashcards in 1.6 bonding Deck (18):
1

1a How do we know that ions exist?

physical properties of ionic compounds (brittle)
electron density maps
electrolysis

2

1b How are ions formed?

electron loss or gain

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1d What is an ionic crystal on a molecular level?

a giant lattice of alternating ions

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1e What is an ionic bond?

electrostatic attraction between oppositely-charged ions

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1f Define 'isoelectronic'.

same electronic structure

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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)

7

1g How does an ionic lattice form?

metal loses electrons
non-metal gains electrons
ions are attracted to one another

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1i What is polarisation (of ions)?

electron imbalance from attraction to other nuclei, causing one end to be more negative than another

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1j Which two factors increase the polarising power of a cation?

radius (smaller radius, more polarising)
nuclear charge (greater charge, more polarising)

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1j Which factor increases the polarising power of an anion?

radius (larger radius, more polarisable)

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1k What does polarisation within ionic compounds lead to?

covalency (more polarised compounds are more covalent)

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1l How does the enthalpy of formation of MgCl2 prove that it is more stable than MgCl or MgCl3?

[waiting on answer from nmb]

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2a How is a covalent bond formed?

attraction between nuclei and shared pair(s) of electrons inbetween

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2ai How can we tell that covalent bonds are strong?

giant covalent structures (e.g. diamond) have high sublimation points

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2aii How do electron density maps prove the strength of covalent bonds?

buildup of electrons between nuclei - attraction

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2b What is a dative covalent bond?

a covalent bond wherein both of the electrons inbetween came from the same electron

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3a What do metals look like on a molecular level?

giant lattices of metal ions and delocalised electrons

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3b Describe metallic bonding.

attraction between metal ions and delocalised electrons