C3 Structure and bonding Flashcards
The ionic bonds between the charged particles result in an arrangement of ions called what?
a giant structure or giant lattice
What is between the oppositely charged ions in giant structures of ions arranged in a lattice?
attractive electrostatic forces that act in ALL directions and are very strong
What does the attractive electrostatic forces do?
holds the ions in the lattice together very tightly
It takes a lot of what to break up a giant ionic lattice and why?
Energy- lots of strong ionic bonds to break
How do we separate ions?
have to overcome all those electrostatic forces of attraction acting in all directions
Hard to separate means ionic compounds have..
high boiling+melting points
What happens to the ions once enough energy is supplied to separate the ions from the lattice
They become mobile and start to move around (solid to liquid)
Ions are ___ to ___ anywhere in the liquid
free
move
Why can’t a solid ionic compound conduct electricity?
ions are held in fixed positions in the lattice; ions cannot move around
They vibrate on the spot
Many but not all ionic compounds will dissolve in water. When an ionic compound is dissolved in water, what happens?
lattice is split up by the water molecules. -> ions free to move around within the solution formed
What is molten?
liquefied by heat.
What is covalent bonding
When non-metals react together, their atoms share pairs of electrons to form molecules
The atoms of non-metals generally tend to gain what?
gain electrons to achieve stable electron structures
When non-metals react together, neither atom can give away electrons. So where do they get their electronic structure?
They get their electronic structure of a noble gas by sharing electrons
In covalent bonding, the atoms in the molecules are then helped by what?
Shared pairs of electrons
The strong bond between the shared pairs of electrons are called?
covalent bonds
Many substances containing covalent bonds consist of what?
small molecules e.g. h20
Some covalently bonded substances are very different to those small molecules. What do they have?
giant structures - where huge numbers of atoms are held together by a network of covalent bonds
what are these covalent bonds in giant structures sometimes referred as?
macromolecules
Diamond has what sort of structure?
giant covalent structure
In diamond. how many covalent bonds does the carbon atom form?
4 covalent bonds w its neighbours
Since the carbon has 4 covalent bonds, what does this result in?
a rigid giant covalent lattice
What are dot and cross diagrams for?
to show bonding in covalent compounds
Electrons drawn in the ____ between the outer orbitals of two atoms are ____ between atoms in covalent bonding
overlap
shared
What are dot and cross diagrams useful for?
showing which atoms the electrons in a covalent bond come from
What is a drawback of dot and cross diagrams
Doesn’t show relative SIZES of the atoms
or how the atoms are arranged in space
Displayed formula is useful for?
shows how atoms are connected in LARGE molecules
drawback of displayed formula?
does not show 3d structure of the molecule
or which atoms the electrons in the covalent bond have come from
What does the 3D models show?
the atoms, the covalent bonds and their ARRANGEMENT in space