module 3: 7.3 periodic trends in bonding and structure

Question 1

how are electrons spread in solid metallic structures

Answer 1

in metallic bonding, each atom donates its negative outer-shell electrons to a pool of delocalised electrons throughout the whole structure.
the positive ions (cations) left behind consist of the nucleus and the inner-electron shells of the metal ions

Question 2

define the term metallic bonding

Answer 2

metallic bonding is the strong electrostatic attraction between cations and delocalised electrons

Question 3

what do metal atoms held together by metallic bonding form

Answer 3

giant metallic lattice

Question 4

properties of metals

Answer 4

• strong metallic bonds - the attraction between cations and delocalised electrons
• high electrical conductivity (solid and liquid and molten)
• high melting and boiling points

Question 5

describe what bonds are in giant metallic structures

Answer 5

strong metallic bonds between cations and delocalised electrons

Question 6

describe what bonds are in giant covalent structures

Answer 6

strong covalent bonds between atoms

Question 7

describe what bonds are in simple molecular structures

Answer 7

weak London forces between molecules

Or vdw

Question 8

describe the structure of diamond

Answer 8

• each carbon is covalently bonded to 4 other carbon atoms forming a tetrahedral shape
• high melting point
• extremely hard
• good thermal conductor (vibrations travel easily through the stiff lattice)
• it cant conduct electricity
• insoluble due to strong covalent bond

Question 9

describe the structure of graphite

Answer 9

• weak forces between the layers
• delocalised electrons meaning they are free to move, meaning electric current can flow
• very high melting point
• insoluble due to strong covalent bond
• layers are far apart

Question 10

describe the structure of graphene

Answer 10

• one layer of graphite
• transparent and light
• extremely strong
• has delocalised electrons (best known electrical conductor)