Structure and Bonding Flashcards
(36 cards)
What are the three types of bons?
Covalent, ionic and metallic
What happens to the electrons in an ionic bond
They are transferred
What type of elements form ionic bonds?
Metals + Non metal
What happens if an atom loses an electron?
If an atom loses an electron it gains a positive charge (positive ion).
What happens if an atom gains an electron?
If an atom gains an electron it gains a negative charge (negative ion).
Describe the structure and bonding in an ionic compound?
- Giant Ionic Lattice
- Held together by strong electrostatic forces of attraction
- Between oppositely charged ions
State and Explain the melting and boiling points of ionic compounds
- High
- Due to Strong Electrostatic Force of attraction
- Takes a lot of energy to break
How can you determine the charge of an element in an ionic bond?
Group 1 = +1 Group 2 = +2 Group 3 = +3 Group 5 = -3 Group 6 = -2 Group 7 = -1.
Why doesn’t Group 4 form ions?
Group 4 doesn’t form ions because it requires too much energy to transfer 4 electrons.
Why doesn’t Group 0 form ions?
Group 0 doesn’t form ions because it already has full outer shells and is stable.
When do ionic compounds conduct electricity?
- Liquid or Aqueous form
- Ions are free to move and carry a charge.
What is covalent bonding?
Covalent bonding happens between two nonmetals. They share electrons to gain full outer shells.
What are the types of displaying covalent bonds?
There are three types of displaying covalent bonds: Dot and Cross Display Formula and Molecular Formula.
What kind of substance have covalent bonds
Small molecules and Giant covalent substances
What are the properties of simple molecular structures?
They have low melting points due to weak intermolecular forces and do not conduct electricity as there are no charged particles.
How many bonds does carbon have
4
Why do most covalent structures not conduct elecricity?
As there are non free electrons or ions that are free to carry a charge
Why do diamond and silicon dioxide have high melting points?
- Giant Structure
- Strong covalent bonds between atoms
- Require lots of energy to break
How does graphite conduct electricity?
- Each carbon bonds to 3 other carbons in layers
- One 1 per carbon in delocalised
- Therefore free to carry a charge
Why can graphite be a lubricant ?
Weak intermolecular forces between the layers are free to slide over each other
Structre of a small molecule
Strong covalent bonds between atoms
Weak intermolecular forces holding the molecules together
State and Explain melting points of small molecule
- Low
- Intermolecular forces are weak
- Take little energy to break
Why do larger molecules have higher melting points
Intermolecular force strength grows with increased size
What is graphene
One layer of graphite
