Bonding, Structure and the Properties of Matter Flashcards
Paper 1 - C2
What are the 3 states of matter?
Solid, Liquid and Gas
What are the features of solids and how are the particles arranged in solids?
-Solids are extremely hard to compress, this is because the particles in a solid are packed together in a regular pattern.
-Solids have a fixed shape and they cannot flow from place to place, this is because in a solid the particles can vibrate but they cannot move from place to place.
What are the features of liquids and how are the particles arranged in liquids?
-Liquids are extremely hard to compress, that is because the particles are close together with not many spaces between them.
-Liquids take the shape of their container and they can flow from place to place, this is because the particles in a liquid can move.
What are the features of gases and how are the particles arranged in gases?
-Gases are extremely easy to compress, that is because particles in gases are widely spaced.
-Gases spread out and fill the space of their container, that is because the particles in a gas move quickly and randomly.
How can we change states?
By putting in or taking out energy.
What happens when we heat a solid?
-It can change state to a liquid (Melting) and this takes place at the melting point.
-During the state change the particles in a liquid are moving around so they’ve got more kinetic energy than the particles in a solid.
-Which means that we have to put energy in to convert a solid into a liquid.
-This energy is needed to break the forces of attraction between the particles in a solid and once they are broken the particles can now move around.
Key Fact:
The stronger the forces of attraction between the particles the more energy we have to put in to break these forces and the higher the melting point.
What happens when we cool a liquid?
-It can change state from a liquid to a solid (Freezing), freezing takes place when we cool a liquid back down to its melting point.
-When a substance freezes the forces of attraction between the particles reform.
What happens when we heat a liquid?
-It will change state from a liquid into a gas (Boiling), boiling takes place at the boiling point.
-And if there are strong forces of attraction between the particles then the boiling point will be high.
-That is because it takes a lot of energy to break those strong forces of attraction and boil the liquid.
What happens when we cool a gas?
-It can change state from a gas into a liquid (Condensing), condensing takes place at the same temperature as boiling (boiling point).
-And when a substance condenses the forces of attraction between the particles reform.
Key Facts:
-Elements react in order to achieve a full outer energy level.
-By doing this, they achieve the stable electronic structure of a noble gas.
What happens when a Group 1 metal and a Group 7 non-metal react?
Ionic bonding takes place, Group 1 metals lose one electron forming one positive ion, Group 7 non-metals gain one electron forming one negative ion, now both ions have a full outer shell.
What happens when a Group 2 metal and a Group 6 non-metal react?
Ionic bonding takes place, Group 2 metals lose two electron forming a 2+ positive ion, Group 6 non-metals gain two electron forming 2- negative ion, now both ions have a full outer shell.
What do ionic compounds form?
They form Giant structures called a giant ionic lattice and they are three dimensional structures.
What is in a giant ionic lattice?
-In a giant ionic lattice, every positive ion is surrounded by negative ions and every negative ion is surrounded by positive ions.
-There are also strong forces of attraction between the positive and negative ions called electrostatic forces of attraction and are also called ionic bonds.
-These forces hold the positive and negative ions in place.
What directions do ionic bonds act in?
All directions
What are the properties of Ionic Compounds?
-Ionic compounds have very high melting and boiling points. That is because the strong electrostatic forces of attraction require a great deal of heat energy to break.
-They cannot conduct electricity when they are solids because the ions are locked in place by the strong electrostatic forces of attraction.
-But they can conduct electricity when they are melted or dissolved in water because the ions can now move and carry the electrical charge.
What happens when we heat an ionic solid?
The particles vibrate and when the particles vibrate with enough energy the electrostatic forces of attraction break and the solid melts. It also takes a great deal of heat energy for these to break as the electrostatic forces between the ions are very strong.
What is covalent bonding?
When non-metal atoms bond together and is a strong bond.
How can we show covalent bonding?
Dot and Cross diagrams or Stick diagrams
What are the properties of small covalent molecules?
-They have a low melting and boiling point and this means that they are usually gases or liquids at room temperature.
-They do not conduct electricity as they do not have an overall electric charge.
Why do small covalent molecules have a low melting and boiling point?
-The atoms in each molecules are held together by strong covalent bonds.
-Secondly there are very weak intermolecular forces between one molecule and another.
-As we increase the temperature the vibration of the molecules increases and at a certain point it will break the weak intermolecular forces holding the molecules to each other.
-At this point the molecules turn to a gas (boil) and the bonds do not take a great deal of energy to break because of the weak intermolecular forces.
Why are Giant covalent substances are always solid at room temperature?
Because all giant covalent substances have high melting and boiling points as they have millions of strong covalent bonds and it takes a great deal of energy to break all of the bonds.
What is diamond formed by?
Carbon
What does diamond consist of?
Huge number of carbon atoms joined by covalent bonds which makes diamond an extremely hard substance.
Why does it take a great deal of energy to melt diamond?
We need to break the huge number of covalent bonds in the diamond which makes diamond have a very high melting and boiling point.
Why can diamond not conduct electricity?
All of the outer electrons are in covalent bonds which means that diamond has no free electrons to carry electrical charge