Bonding, Structure and properties and matter Flashcards
When are ions made
When electrons are transferred
Why do atoms lose/ gain electrons
To gain full outer shells
What groups are most likely to form ions
1,2 (lose electrons to make positive) and 6,7 (gain electrons to make negative)
Explain ionic bonding
When a metal and a non metal react together. The metal loses electrons to form a positive ion and the non metal gains electrons to form a negative ion. The oppositely charges ions are attracted by strong electrostatic forces in an ionic bond
What type of structure are ionic compounds
Giant ionic lattice- organised regularly
Prooperties of ionic compounds
- High melting/ boiling points
- Can’t carry charges unless molten
- Some ionic compounds dissolve in water so they’ll carry electric charge
What is empirical formula
The simplest ratio of atoms in an element in whole numbers
Explain covalent bonding
Non metals bond with covalent bonding
Positively charged nucleus of atoms are attracted two shared pairs of electrons, with electrostatic forces- strong bonds
- Each covalent bond provides an extra electron for each atom
What is the display formula
The one with the letters and sticks connecting them
What are covalently bonded substances often labelled
Simple molecular substances
Properties of covalently bonded substances
- Low melting/ boiling point as there are weak intermollecular forces
- Often liquids/ gases at room temperature
- As molecules get bigger, the strength of intermolecular forces get bigger so they have higher melting/ boiling points
- Don’t conduct electricity
What is a polymer
A long chain of a repeating unit
What is different in giant covalent structures to simples and what effect does that have on melting point
In giant covalent structures, all of the atoms are bonded, which means the melting points are very high
Structure of diamonds
Giant covalent- all carbon atoms are bonded to 4 other atoms
Strucure of graphite
Each carbon is bonded to 3 others and there is one delocalised electron
Properties of diamond and why (2)
- Each carbon is bonded to 4 others- which means it is hard
- Doesn’t conduct electricity because there are no free electrons
Properties of graphite and why
- No bonds between layers so they can easily slip over each other
What is a fullerene
A sphere of carbon
Uses of fullerenes (4)
- Can be used to ‘cage’ other molecules so they can be used to deliver drugs into bodies
- Can form nanotubes
- Have high tensile strength (don’t break when stretched)
- Conducts thermal and electrical energy
Explain metallic bonding
- Electrons in the outer shell of metals mean that the metals form positive ions
- The sea of delocalised electrons and positive metal ions have large electrostatic forces of attraction
- Delocalised electrons hold together the lattice
Properties of metals (3)
- Solid at room temperature
- Good conductors of electricity and heat
- Most metals are malleable
Why are alloys harder than pure metals
Different sized atoms distort the layers of metal atoms making it more difficult for the to slide over each other so the metal is harder
What are the 3 states of matter
Solid liquid gas
Properties of solids (3)
- Strong forces which hold particles in fixed positions in a regular arangement
- Particles dont move from their positions
- The otter solids get, the more they vibrate
