Structure and bonding (don't use this set) Flashcards
What are bonds?
Forces of attraction that hold atoms together
What happens when bonds form between atoms?
When bonds form between atoms, energy is released from the atoms which makes them more stable (less reactive)
What’s an ion?
A charged particle
What holds the ions together in an ionic bond?
Electrostatic forces
What are ionic compounds held together by?
Electrostatic forces of attraction between oppositely charged ions
What’s a giant ionic lattice?
Found in ionic compounds: Ions are packed together in a regular arrangement with alternating oppositely charged ions in all directions
What can ionic compounds form when solid?
Crystals due to their regular lattice structure
What does it mean when an ion ends in ‘-ate’ or
‘-ite’ ?
The ion contains oxygen as well as another element
What’s a polyatomic ion?
An ion composed of two or more atoms
Do ionic compounds have high or low melting and boiling points? - why?
High melting and boiling points
The strong electrostatic forces of attraction between ions require more energy to be overcome
Do ionic compounds conduct electricity?
Yes- only when molten or dissolved in water because the ions are free to move
What conditions should be met for a substance to conduct electricity?
- must contain charged particles
- particles must be free to move
What’s a covalent bond?
A shared pair of electrons
What’s a molecular substance?
Contains a group of atoms that are held together by strong covalent bonds
What are atoms in molecules held together by?
Strong electrostatic forced of attraction between the positive nuclei and negative electrons in the bonded atoms
What are the properties of a compound influenced by?
Its atoms
Its type of bonding
What’s a compound?
A substance made up of two or more elements chemically combined
What structure do substances containing covalent bonds have?
Simple molecular
In terms of covalent bonding, why does water have a low boiling point?
Although molecules are held together with strong electrostatic forces of attraction, the intermolecular forces between molecules are weak
Can simple molecules carry an electric current?
No - They have no overall charge.
The covalent bonds, the strong forces between electrons and the nuclei holds the electrons in place
So, the electrons can’t flow and carry the current
What are monomers?
Small, simple molecules that can be joined in a chain to form a -polymer-
What are the boiling points like in polymers?
Longer polymers have higher melting points than shorter ones because there are more intermolecular forces between them
What happens in metallic bonding?
Metals lose electrons to form positive ions and delocalised electrons
What’s a metallic bond?
The strong electrostatic attraction between the positive ions and delocalised electrons
What’s an ionic bond?
Strong electrostatic force of attraction between oppositely charged ions
Which types of elements form ionic bonds?
Metal and non metals
