C2 - Bonding, Structure, & Properties Of Matter Flashcards
What is an ion?
- Cation
- Anion
An atom that has gained or lost electrons.
Electrons are negative;
Cation - It has lost electrons so it will be positively charged.
Anion - It has gained electrons so it will be negatively charged.
What is ionic bonding?
Bonding between oppositely charged particles, held together by electrostatic forces of attraction.
The positive ions are often metals and the negative ions are often non-metals.
Describe how an ionic bond forms between a metal atom and a non-metal atom, in terms of electron transfer.
The metal atom loses electrons to form a positively charged ion.
The non-metal atom gains these electrons to form a negatively charged ion.
These oppositely charged ions form an ionic bond, due to the electrostatic forces of attraction between them.
Explain why ionic compounds conduct electricity when molten, but not when solid.
The ions in a solid ionic compound are held in place in a giant lattice structure, so they cannot move around.
When an ionic compound melts, the ionic bonds break and the ions become free to move and can carry an electric charge.
Do ionic compounds have high or low melting points? Why?
Ionic compounds have high melting points, because of the strong electrostatic forces of attraction between the ions.
What is the structure of ionic compounds?
A regular lattice structure which is closely packed and held together by strong electrostatic forces of attraction in all directions.
What is covalent bonding?
Bonding between 2 non-metals, that share a pair of electrons.
What are the 2 forms of covalent bonding structures?
. Simple molecular
. Giant lattice - (such as polymers and giant covalent structures)
What are simple molecules?
A structure containing a few distinct groups of atoms, which are held together by covalent bonds.
What are some common examples of simple molecular substances?
Hydrogen
Oxygen
Methane
Chlorine
Nitrogen
Water
Hydrogen chloride
Describe the properties of simple molecular substances?
Very strong covalent bonds between atoms
Very weak forces of attraction between molecules = very low melting & boiling points because molecules are easily parted from each other
Don’t conduct electricity because there aren’t charged so there are no free electrons or ions
As molecules get bigger, the strength of intermolecular forces increases and more energy needed to break them
What is a polymer?
Lots of small units linked together to form a long molecule that has repeating sections.
Describe the structure of polymers
What is a giant covalent structure?
What are the main examples of giant covalent structures?
A macromolecule (a molecule containing a very large number of atoms) where all the atoms are bonded to each other by strong covalent bonds
Diamond, graphite, and silicone dioxide.
What is silicone dioxide?
