Bonding, structure, and the properties of matter Flashcards
What happens to the size of intermolecular forces as the size of molecules increase?
The size of intermolecular forces increase (hence higher melting and boiling points for larger molecules)
What are the limitations of the following diagrams to represent ionic structures? Dot and Cross Ball and Stick
• Dot and cross: Doesn’t show the structure of the ionic compound, the size or arrangement of ions. • Ball and stick: Suggests gap between ions which aren’t in fact there.
Describe the structure and bonding of Graphite.
• Giant covalent structure • Each carbon forms three covalent bonds with other carbon atoms • Forms layers of hexagonal rings • No covalent bonds between layers • One electron from each carbon atom is delocalised
What state are most polymers at room temperature? Why?
• Solid • Because they are large molecules, with strong intermolecular forces, hence relatively high melting and boiling points (compared with small molecules).
Diamond and graphite are made out of a single element. Name this element.
Carbon
Why do small molecules usually have relatively low melting and boiling points?
• They have weak forces between molecules (intermolecular forces) • It is the intermolecular forces that are overcome, not the covalent bonds, when the substance boils.
Describe how sodium and chlorine bond to form sodium chloride.
• The sodium atom loses one electron to become a sodium ion • The chlorine atom gains one electron to become a chloride ion • The positive sodium ion is attracted to the negative chloride ion to form sodium chloride.
What charge do the ions of elements in the following groups have?: a) Group 1 b) Group 2 c) Group 6 d) Group 7
a) Group 1: + b) Group 2: 2+ c) Group 6: 2- d) Group 7: -
What are cylindrical fullerenes called and why are they useful?
• Nanotubes • They have a high length to diameter ratio making them useful for nanotechnology, electronics and materials.
Do metals have high or low melting points and boiling points?
High melting and boiling points
Describe the properties of Diamond.
• Hard • Very high melting point • Doesn’t conduct electricity
Describe the structure and bonding of Diamond.
• Giant Covalent Structure • Each carbon forms four covalent bonds with other carbon atoms
What type of bond exists between metals and non-metals in a compound?
Ionic Bond
What element are all fullerenes made from?
Carbon
What is graphene?
A single layer of graphite
Why are metals good conductors of heat and electricity?
They have delocalised electrons that can carry the charge (in terms of conducting electricity) or transfer energy (in terms of conducting heat)
What type of bond exists in non-metal elements and compounds?
Covalent Bond
In which type of bond are electrons transferred?
Ionic bond
What bonds must be overcome in order to melt or boil giant covalent structures?
The strong covalent bonds between the atoms.
Describe the structure and bonding in a metal.
• Metallic bonding • Strong metallic bonds • Giant structure of metal atoms in regular pattern • Outer shell electrons are delocalised
When atoms gain or lose electrons to become ions, they will have the electron structure of what group of elements?
Noble gases
What is the name for the forces that exist between ions in an ionic bond?
Electrostatic forces
In which type of bond are electrons shared?
Covalent bond
What type of bonding exists in metallic elements and alloys?
Metallic bonding
