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Flashcards in C4c Deck (7)
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1
Q

What do ionic compounds form?

A
  • ionic bond for between metals and non-metals and always make giant ionic lattices
  • ions form a closely packed
  • ions not free to move so the compounds do not conduct electricity when solid
  • very strong chemical bonds between all the ions
2
Q

What are the properties of NaCl and why?

A

-giant ionic structure
-high melting and boiling point due to very strong attraction between oppositely charged ions in the giant structure
when melted ions are free to move and will conduct electricity
-dissolves to form solution that conducts electricity (ions dissolve and separate so are free to move in the solution, so they carry electric current)
-Na+ and Cl- ions

3
Q

What are the properties of MgO and why?

A
  • giant ionic structure
  • high melting and boiling point due to very strong attraction between oppositely charged ions in the giant structure
  • Mg2+ and O2- ions (double the charge of NaCl
  • higher melting point than sodium chloride:
  • as it has double the charge of NaCl, so the attraction is harder to overcome
  • O2- ions are smaller than Cl- ions, so ions in MgO more dense , also making the attraction harder to overcome
  • when melted ions are free to move and will conduct electricity
4
Q

What are ions and how are they formed?

A
  • charge particles, can be a single atom(Cl-) or a group of atoms(NO-3)
  • non metal: gain electrons to form negative ions
  • metal: lose electrons to form positive ions
5
Q

What is ionic bonding?

A

-atoms losing or gaining electrons to form charged particles (ions) which are then strongly attracted to each other (because of the attraction of opposite charges)

6
Q

Why are the boiling and melting points of molecular substances low?

A
  • atoms within the molecules are help together by very strong covalent bonds
  • by contrast, the forces of attraction between these attractions are very weak
  • because of these feeble intermolecular forces, they have very low boiling and melting points
7
Q

What are some properties of molecular substances?

A
  • substances formed from covalent bonding usually have simple structures (CO2)
  • most are liquids or gases at room temperature
  • don’t conduct electricity, because there are no free electrons or ions