Structure And Bonding Flashcards
What is ionic bonding?
Ionic bonding is a chemical bond that involves the electrostatic attraction between oppositely charged ions. It is between a metal and a non metal
What is the structure all ionic compounds form?
Giant Ionic lattices
What is a lattice?
An ionic structure where ions are arranged regularly with no gaps.
What holds together ions in a lattice?
Electrostatic forces of attraction
What state must ionic substances be in to conduct electricity?
Molten or dissolved
What are properties of ionic compounds?
- Solid at room temperature
- Conduct electricity when molten improve dissolved
- Soluble in water
- Very high melting points
Why can ionic substances conduct electricity when molten or dissolved?
As the charged particles are free to move around (as the lattice is broken) and so can carry and charge
Why do ionic substance have high melting and boiling points?
The strong electrostatic attractions between oppositely charged ions require a lot of energy to break apart
What is covalent bonding?
When two non metals react, both wanting to gain electrons to make a full outer shell, so they share a pair of electrons
How man bonds do non metals have?
The same number of electrons on their outer shell
What are properties of simple molecular compounds?
- Low melting and boiling points
- Do not conduct electricity (other then water)
- Low density
- Soluble
What are properties of giant molecular compounds?
- High melting and boiling points
- Generally do not conduct electricity
- High density
- Insoluble
Why do simple molecular have low melting and boiling points?
A structure when only the weak intermolecular forces between molecules are broken (not strong covalent one). So only small amounts of energy are needed to break the weak forces.
Why can’t simple molecular conduct electricity?
As there are no free charged particles (only ions or electrons) to allow a current to flow.
What is the structure of polyethene?
Between the carbon atoms there are strong covalent bonds and between the layers there are weak intermolecular forces
Why do polymers have high melting and boiling points?
As the longer the chain length, the more intermolecular forces between the monomers, meaning more energy is needed to break them apart
What are allotropes?
Allotropes are different structural forms of the same element