Unit 3 Flashcards
Why is an Ion charged
Because it has an unequal number of protons and electrons
What groups ionic bonding between
Metals and non-metals
What is an ionic bond
Went to ions have opposite charges so they attract each other the force of attraction between them is strong
What form positive ions
Hydrogen and metals
What do non-metals form
Negative ions and their names end in -ide
Why do groups four and five not usually form ions
Because they would have to lose or gain several electrons and that would take too much energy
Why does group 0 not form ions
Because they have a full outer shell already
What type of metals town form more than one ion
Transition metals
What are compound ions
When ions can be formed from groups of joined atoms
What are the properties of an ionic compound
Ionic compounds have high melting and boiling points. This is because ionic bonds are very strong, so it takes a lot of heat energy to break up the lattice.
Ionic compounds are usually soluble in water. The water molecules can attract the ions away from the lattice. The ions can then move freely, surrounded by water molecules.
Ionic compounds can conduct electricity when they are melted or dissolved. When melted the lattice breaks up on the ions are free to move. Since they are charged, this means they can conduct electricity. The solutions of ionic compounds conduct electricity to because they are also free to move.
What is a lattice?
Ionic lattice structure each positive ion is surrounded by several negative ions
What is covalent bonding between?
Nonmetals only since nonmetals need to gain electrons
What is a single covalent bond
When a pair of electrons are shared
What is a double covalent bond
Two pairs of electrons are shared
What is a triple covalent bond
When 3 Pairs of electrons are shared
What is A covalent compound
When atoms of different elements share electrons with each other
Why are molecules in a covalent bond not flat
Because each electron repel each other and try to get as far apart from each other
What are the solids in a molecular substance
Crystaline
What happens when you cool down and molecular liquid or gas
The molecules lose energy so they start moving slowly and at the freezing point, they form a lattice
What are the properties covalent bonding
Have lower melting and boiling points. This cause the forces between the molecules molecules are weak
Do not conduct electricity. This is because molecules are not charged, so they cannot conduct, even when melted
What is a giant covalent structure for a macromolecules
Made of billions of atoms bonded together in a covalent structure
Diamond-giant covalent structure
Diamond is made of carbon atoms held in a strong lattice. Each carbon atom forms a covalent bond to four others. Eventually billions of carbon atoms bond together To form a Crystal of diamond
What are Diamond Properties
Hard because each atom is held by for strong bonds
It has a very high melting point because of the strong bonds
It can’t conduct electricity because there are no free electrons to carry the charge
What is similar to diamond
Silica
Graphite
Like diamond graphite is made only of carbon atoms. So Diamond is and graphite are allotropes of Carbon (means they are two forms of the same element). Graphite, unlike diamond, is one of the softest solids on Earth. In graphite, each carbon atom forms a covalent bond to 3 others. This gives rings of six atoms
What are graphite properties
Soft and slippery because the sheets can slide over each other
It’s a good conductor of electricity because each carbon has for outer electrons and graphite bond three only so the four electron is free to move carrying a charge.
What are the uses of diamond
Jewellery
For tools for drilling and cutting
What are the uses of silica
In sandpaper
For making glass and lenses
In bricks for lining furnaces
What are the uses for graphite
As a lubricant for engines
For pencil lead which is mixed with clay
For electrodes and connecting brushes in generators
What are the properties of silica
They are hard and can scratch things
Hard .let’s light through
High melting point
What is a metallic bond
Is the force of attraction between free electrons and metal ions
Why do metals have high melting points?
This is because it takes a lot of heat energy to break up the lattice
Why metals are malleable and ductile
Malleable-they can be bent and pressed into shapes
Ductile-They can be drawn into wires
This is because the layers can slide without the metallic bond breaking, because the electrons are free to move to
Why are metals good conductors of heat
It’s because the free electrons take in heat energy, which makes them move faster and they quickly transfers heat through the metal structure
Why are metals good conductors of electricity
This is because the free electrons can move through the lattice Carrying the charge
