C2 Flashcards
How are ions made?
By the transfer of electrons
What are ionic compounds?
Ionic substances form giant ionic lattices containing oppositely charged ions. They have high melting and boiling points, and conduct electricity when melted or dissolved in water.
What is ionic bonding?
The transfer of electrons.
What is covalent bonding?
The share of electrons.
What are covalent bonds?
The shared Bonds between non-metals only. The positive Nuclei is attracted to the shared pair of electrons by electrostatic forces-making them very strong.
Simple molecular substances are made my covalent bonds.
What are simple molecular substances?
Simple molecular substances are made up of molecules containing a few atoms joined together by covalent bonds
What are polymers?
Long chains of repeated units joined together by covalent bonds
What are 4 allotropes of carbon?
- graphite
- graphene (one layer of graphite)
- diamond
- buckminsterfullerene (or just fullerenes)
What is metallic bonding?
It is the bond between only metals, which involves a delocalised (free) electron. These consist of giant structures.
What are alloys?
A mixture of two or more metals or a metal and another element. Alloys are harder and so more useful than pure metals.
What are some properties of simple molecular substances? (Covalent bonds)
- atoms in molecules held together by strong covalent bonds but attraction between these molecules are v week.
- melting and boiling points are low as molecules are easily parted.
- molecular compounds don’t conduct electricity as they aren’t charged and have no free electrons.
- usually gas or liquid at room temp.
What are some properties of ionic compounds?
- high melting and boiling points due to many strong bonds between ions
- when solid, ions aren’t free to move so can’t conduct electricity, however, when liquid ions are free to move so can conduct electricity.
- dissolve easily in water so are free to move and can conduct an electric current.
