Topic 2 - Bonding Flashcards
What does an ionic bond form between?
metal and non-metal
What does a covaltent bond form between?
non-metal and non-metal
What does a metallic bond form between?
metal and metal
How does an ionic bond form?
The metal loses electrons to become a positively charged ion, the non-metal gains electrons to become a negatively charged ion
How does a covalent bond form?
non-metals share pairs of electrons to gain full outer shells
How does a metallic bond form?
Metals lose their outer shell elctrons into a sea of delocalised electrons
Elements in group 0 will form ions with what charge?
Group 0 don’t form ions because they already have a full outer shell
When are elements stable?
When they have a full outer shell of electrons
In ionic bonding, how are ions held together?
Electrostatic forces of attraction
Explain how Calcium Oxide forms. Remember Calcium is in gorup 2 and Oxygen is in group 6
Calcium loses electrons becoming a positive ion and Oxygen gains electrons becoming a negative ion
Do ionic compounds have high or low melting points?
Ionic compounds have high melting points
Why do ionic compounds have high melting points?
Ions are held together by strong electrostatic forces of attraction
How are ions arranged in an ionic compound?
Giant ionic lattice
Can ionic compounds conduct electricity?
Yes but only when molten or dissolved in water
Why can ionic bonds only conduct electricity when molten or in a solution?
When solid, the ions in an ionic compounds can’t move. When molten or in solution th ions are free to move
Define the term: dissociate
To separate into separate ions. We talk about dissociation in terms of ions in ionic compounds dissociating when in a solution
True or False: All simple covalent molecular substances are insoluble in water
False, Some simple molecular substances are soluble and some are insoluble
Is a covalent bond strong?
A single covalent bond is very strong. It is extremely hard to try and bbreak a bond where they are sharing electrons.
Why don’t simple molecular substances conduct electricity?
There is no charged ions and there is no free electrons that can move to carry electricity
Why do simple molecular substances have low melting and boiling points?
Simple molecular substances have low melting and boiling points because there was weak intermolecular force of attraction between moleculs that can easily be broken.
H2 and CH4 are both covalent compounds. Which would have the highest boiling point?
CH4 would have the highest boiling point. The larger the molecule the stonger the intermolecular forces, meaning the more energy needed to break them.
Define the term: allotrope
Different forms of the same element, for example diamond and graphite are both made from carbon
What element is graphite made from?
Carbon
What element is damond made from?
Carbon
What is the structure of diamond?
Diamong is a tetraheadral structure, where each carbon is covalently bonded to 4 other carbons
What is the structure of graphite?
Graphite is layers of graphene sheets, with forces acting between the sheets. Each carbon is bonded to 3 other carbon atoms in a hexagonal structure
What is the difference between graphite and graphene?
Graphene is a single layer of hexagonal lattice structure, where a carbon is bonded to 3 other carbons. Graphite, is layers of graphene sheets
Can diamond conduct electricity?
No. There are no free electrons in diamond
Can graphite conduct electricity?
Yes. There are free electrons that can move throughout the structure
Why do giant covalent substances have high melting points?
They have high melting points because of the strong covalent bonds between the atoms
Explain how the structure and bonding of graphite makes it a suitable material for lubricants.
Graphite has a layered structure, with only weak forces of attraction between the layers. The layers can break away from each other, makng graphite soft and slippery
Describe the structure of fullerenes
Fullerenes are molecules of carbon, shaped likeclosed tubes or hollow balls. They have a huge surface area, so many catalyst molecules could be attached to each fullerene
Why is graphite used for electrodes?
Graphite has the ability to conduct electricity due to the free electrons. Carbon is also unreactive which makes it safer to use in electrodes
Where on the periodic table are metals found?
Towards the left of the periodic table
Describe the bonding in a metal
The bonding in a metal consists of strong electrostatic forces of attraction between positive metal ions and the delocalised electrons.
Explain why metlas can conduct electricity
The have delocalised electrons that can pass through the structure
Explain why metlas can conduct heat
The have delocalised electrons that can pass through the structure
Explain why metals are malleable and ductile
Mtels have a layered structure. The layers can slide across each other, meaning when a pressure is applied the layers move.
Explain why metals have a high melting and boiling point
Metals ions and the delocalised elctrons are held together by strong electrostatic forces of attraction. The electrostatic forces need a large amount of energy to be overcome
Define the term: Alloy
An allow is a mixture of metals or a mixture containing at least one metal.
Why are alloys stonger than pure metals?
An alloy has more than one type of atom. The atoms are different sizes, which makes it harder for the layers to pass over each other
What type of ions do metals form?
Metals always form positive ions
What type of ions do non-metals form?
Non-metals always form negative ions
