Bonds, Structure & Properties of Matter (Giant structure and nano science and Ionic, covalent & metallic bond)

• What are the 3 bonds?

  ionic, covalent, metallic
• What is meant for an atom to achieve a greater level of stability?

  The atom obtains a full outer shell of electrons
• Where do ionic bonds take place?

  When metals and non-metals react by transferring electrons
• What do opposite charges attract through?

  Electrostatic forces
• What is an electrostatic force?

  Strong forces of attraction between articles with opposite charges - such forces are involved in ionic bonding
• What are covalent bonds between?

  Non-metal atoms share pairs of electron between each other to obtain a full outer shell of electrons
• What are metallic bonds between?

  Occurs in metals and metal alloys (mixture of metals)
• What is an ion?

  An electrically charged atom or group of atoms formed by the loss or gain of electrons
• Why do atoms lose or gain electrons?

  To obtain a full outer shell
• What are negative ions called and when do they form?

  Anions and form when atoms gain electrons
• What are positive ions called and when do they form?

  Cations and form when atoms lose electrons
• What do all metals lose do to become positively charged ions?

  Lose electrons to other atoms
• What do all non-metals do to become negatively charged ions?

  Gain electrons from other atoms
• What are positive and negative charges held together by?

  By strong electrostatic forces of attraction between oppositely charged ions - this is what hold ionic compounds together
• How are lattices formed by?

  Ionic compound consist regular arrangement of alternating positive and negative ions in which the ions are tightly packed together
• What holds the lattice together?

  Strong electrostatic forces of attraction are present between oppositely charged ions
• Structure and bonding of ionic substance


  Giant ionic 3D lattice, electrostatic attraction between + ions and - ions
• Diagram of ionic substance structure ]

  
• Why do ionic compounds have high melting and boiling points?

  They contain strong electrostatic attraction between oppositely charged ions which require large amount of heat energy to overcome
• When can ionic compounds conduct electricity?

  When molten or in solution
• Why do ionic compounds need to be in molten or in solution?

  So their ions are free to move and carry a charge through the structure. Ionic solids contain ions but are in fixed position so can't move and carry and charge
• Structure of a giant ionic lattice

  
• What do ionic compound form?

  Giant 3D ionic lattice that consists of lots and lots of ions all attracted to each other
• Do ionic substance dissolve in water?

  Depends but yes - when ionic substance dissolve in water the electrostatic attraction between ions will break and ions will separated
• What 2 type of structures can covalent substances form?

  -Giant covalent 3D lattice (a macromolecular)

  -Simple molecular structure
• What are the 3 types of giant covalent structures?

  -Diamond

  -Graphite

  -Silicon dioxide
• diagram of this

  
• What are the properties of a giant covalent substance?

  -High melting and boiling point

  -Not soluble

  -Some can conduct electricity
• Why do giant covalent structures have high melting and boiling points?

  Lots of strong covalent bonds between atoms which require large amount of heat energy to overcome - this is also why they are hard and strong
• Why is graphite softer?

  Graphite is a giant covalent structure but it is softer as graphite is made up of layers of graphene. These layers have weak forces between them which can be easily overcome with little force - this allows layers to slide
• Why are they not soluble?

  As the bonds are too strong
• Which giant covalent substances can't conduct electricity?

  Diamond and silicon dioxide
• Why can't they conduct electricity?

  Don't have any free moving ions or electrons
• Which giant covalent substances can conduct electricity?

  -Graphite

  -Buckminster fullerene
• Why can they conduct electricity?

  In graphite only three electrons per carbon atom are used in covalent bonds so one electron per carbon atom is delocalised. These delocalised electrons can move through the structure and carry a charge
• What are the properties of simple molecular covalent substances?

  -Low melting point

  -Can't conduct electricity
• Why do they have low melting points and boiling points?

  They still have strong covalent bonds HOWEVER they have weak forces between molecules which requires little heat energy to overcome

  
  

  Don't break the covalent bonds only the weak forces
• Why can't they conduct electricity?

  Don't have any free electrons or ions
• Metallic substance structure and bonding

  Giant metallic 3D lattice, strong electrostatic attraction between + metal ions and a sea of delocalised electrons
• Diagram of structure