2. Structure And Bonding Flashcards
(39 cards)
How does ionic bonding work?
In ionic bonding, the atoms become ions by the metal atom losing electrons and the non-metal atom gaining electrons.
How are giant ionic compounds constructed?
They consist of a giant structure of ions arranged in a lattice. The attractive electrostatic forces between the oppositely charged ions act in all directions and are very strong. This hold the ions in the lattice together very tightly.
Do giant ionic compounds have high/low melting and boiling points, why?
They have high melting and boiling points because to separate the ions you have to overcome all the strong electrostatic forces of attraction that act in all directions.
What are the advantages and disadvantages of 3d models?
Advantages- provide a clear, spatial representation
- easier to understand the arrangement of ions in a lattice
Disadvantages- can be complex
- do not show the electron transfer
- students cannot easily create their own
What are the advantages and disadvantages of ball and stick models?
Advantages- clearly show the arrangement of ions and bonds
- the sticks represent the electrostatic attraction between ions
- students can easily create their own diagrams
Disadvantages- do not accurately show the distance between ions, leading to misinterpretations of the
relative sizes of ions
What is covalent bonding?
Covalent bonding is when non-metal atoms share pairs of electrons. These bonds between atoms are strong.
What are some properties of giant covalent structures?
- very high melting and boiling points
- insoluble in water
- apart from graphite, they are hard and do not conduct electricity
Why do giant covalent structures have high melting and boiling points?
They consist of a large network of atoms connected by strong covalent bonds. Breaking these bonds require a significant amount of energy.
Why do simple covalent structures have low melting and boiling points?
The individual molecules are held together by weak intermolecular forces that are easier to separate when heated.
How are the particles arranged in metals?
- regular packing
- close together
- vibrating but NOT moving from fixed positions
How are the electrons arranged in metals?
The electrons are free to move about in the structure- they are delocalised.
What is the metallic bond?
The electrostatic attraction between the positive metal particles and negative delocalised elecctrons
Why do metals have high melting and boiling points?
The metallic bond is very strong and requires a lot of energy to break. There is a strong electrostatic force of attraction.
Why do metals conduct heat?
They have free electrons that are not bounded to the atoms and the electrons collide with the metal atoms, transferring the heat to them.
Why do metals conduct electricity?
An electrical current can flow through the delocalised electrons.
Why are metals malleable and ductile?
The layers of metal ions can slide over each other.
Why are alloys harder than pure metals?
The bigger atoms distort the layers of atoms in the pure metal. A greater force is required for the layers to slide over each other.
What are the properties of particles in a solid?
- regular arrangement
- all particles are touching
- vibrate in a fixed position
- particles have the least energy
What are the properties of particles in a liquid?
- random arrangement
- all particles are touching
- able to flow
- more energy than solids and less energy than gases
What are the properties of particles in a gas?
- random arrangement
- particles move quickly in all directions
- most amount of energy
What are the 3 limitations to the particle model?
- no forces are shown
- particles are not spheres in reality
- the spheres look solid but they are not in reality
When do ionic solids conduct electricity?
When dissolved in a solute as the ions can move more freely
Do simple molecules conduct electricity?
No, because there are no delocalised electrons.
What are the properties of diamond?
- HARD as there is a lot of strong covalent bonds in the lattice
- HIGH MELTING AND BOILING POINTS as there are strong covalent bonds
- DOESN’T CONDUCT ELECTRICITY as there are no delocalised, free to move electrons
