C2.1 Structure & Bonding Flashcards
What is a compound?
A substance made up of atoms of two or more elements, chemically combined together.
Can compounds be seperated by filtering or distilling?
No as these are physical methods and cannot break the bonds.
What type of bond causes metals and non metals to bond?
IONIC BONDS
How do ionic bonds join the two substances?
There is a transfer of electrons from the metal to the non - metal, the metal becomes positively charged and the non-metal is negatively charged and so joining them together.
How do two non - metals bond?
COVALENT BONDS
Is covalent bonding sharing or stealing?
In covalent bonds, the electrons are shared between atoms and so these atoms travel together in pairs or groups called molecules.
What is an ion?
An ion is a positive or negatively charged electron due to a loss or gain of electrons.
What process is the loss of electrons?
Oxidisation
What is reduction?
The gain of electrons
Are ionic bonds taken or shared?
TAKEN
What does OILRIG stand for?
Oxidisation is loss, reduction is gain
What affects the reactivity of an element?
The amount of electrons in its outer shell
The closer the number is to full or empty, the more reactive the element is as it wants to have a full or empty outer shell.
How are ionic bonds arranged?
In an IONIC LATTICE alternating POSITIVE OR NEGATIVE ions joined together with ELECTROSTATIC
What is the significance of the group number?
The group number is the same as the amount of electrons in the outer shell of the element
How do you balance MgCl if Mg has a charge of 2+ and Cl has a charge of 1-?
MgCl2
What happens to the electrons in METALLIC BONDING?
The electrons are shed and delocalised forming a delocalised electron sea.
What are delocalised electrons?
Delocalised electrons are the lost outer shell is electrons, they hold the metal ions / cat ions together and, because they can move, allow electricity to be conducted.
Why are metals able to conduct electricity and bend?
The delocalised electron sea allows electricity to be conducted as when the current enters the electrons repel each other towards the positive end. They are free to move due to the cations.
This also means they can bend as the neat arrangement allows the ions to slide over eachother.
What is the difference between an alloy and a compound?
An alloy is a mixture of 2 or more metals with different properties, whereas compounds are pure substances.
What is a cat ion?
A positively charged metal
Which type of bonding only happens in metals?
METALLIC BONDING
What type of molecule is diamond or graphite?
An allotrope -> giant molecules made up of ONE element built or arranged in different ways
What are the properties of diamond?
Diamond is a giant covalent structure. Regular structure Strong Reflects light Not very reactive
What are the properties of Graphite?
Giant covalent structure Lubricant for bike chains Pencils Hexagonal structures In sheets that can slide from eachother and allow graphite to be deposited (in pencils) 3 strong covalent bonds 4th delocalised bond joins sheets together (weak) can conduct electricity
Why do diamond and graphite have very different properties?
Different structure and shape
Diamond -> 3.53 g/cm3 density, pyramid shape -> very strong and hard wearing -> used for drills + jewellery -> 4 bonds per carbon
Graphite -> 3 bonds per carbon -> delocalised bond allows sheets to slip together-> hexagonal shape -> good conductor of electricty due to loose bonds which also helps in pencils.
