States of matter Flashcards
What are the three states of matter
Solid, Liquid and Gas
Describe the arrangement of particles in solids
Solid particles are close together and touching one another. There are no gaps between them
Describe the arrangement of particles in liquids
Liquid particles are close together and touching one another. However, there are some gaps between them
Describe the arrangement of particles in gases
Gas particles are far apart with big gaps between them
Describe the movement of particles in solids
Solid particles vibrate around their fixed positions and do not move apart
Describe the movement of particles in liquids
Liquid particles are in constant, random movement, bouncing off each other
Describe the movement of particles in gases
Gas particles move freely and constantly collide with each other at very high speeds
What are the conversions between solid and liquid called
Melting (solid to liquid)
Freezing (liquid to solid)
What are the conversions between liquid and gas called
Boiling (liquid to gas)
Condensation (gas to liquid)
What are the conversions between solid and gas called
Sublimation (solid to gas)
Deposition (gas to solid)
Describe the process of melting
The solid is heated and its particles gain kinetic energy and vibrate faster. They start to move further apart and consequently the forces of attraction become weaker. These are no longer strong enough to hold particles in a fixed shape and the solid thus becomes a liquid
Describe the process of freezing
The liquid is cooled down and its particles lose kinetic energy and move around more slowly. They eventually come closer together and since the forces of attraction become stronger, the particles are held into fixed positions
What does the melting temperature of a solid tell us
The melting temperature gives a measure of how strong the attractive forces holding the particles in the solid together are
Why does evaporation occur
Very often particles that have more energy can overcome the forces of attraction holding them together and escape from the surface of the liquid
What are the differences between evaporation and boiling
Evaporation takes place at any temperature above the melting point, while boiling takes place only at the boiling point. Also, evaporation takes place only at the surface, while boiling happens throughout the liquid. Lastly, evaporation doesn’t produce bubbles and is a slower process, while boiling is faster and produces bubbles
What are the three types of particles that exist
Atoms, molecules and ions
What are atoms
Atoms are the smallest particles of an element that exist and can take part in chemical reactions
What are molecules
Molecules are the smallest particles of a substance that have all its properties and can exist on their own. It’s made up of atoms held together by covalent bonds
What is an ion
An ion is a charged particle formed when an atom gains or loses electrons
What is diffusion
Diffusion is the movement of particles from areas of high concentration to areas of low concentration
What can affect the rate of diffusion of gases
The mass of the gases involved can affect the rate of diffusion
What can you tell about the masses of ammonia and hydrogen chloride gas based on the experiment between them
Ammonia gas is lighter than hydrogen chloride. The white gas formed is closer to the end of hydrogen chloride, indicating that ammonia traveled a greater distance in the same amount of time. This shows that is lighter and was able to diffuse much faster
What determines whether a substance dissolves in a solvent
The forces of attraction in the solute and the solvent are broken and new forces are formed between them. If these new forces between the solute and the solvent are stronger than the old ones, then the solute can dissolve
What is a saturated solution
A saturated solution is one that can’t dissolve any more solute at a specific temperature
Define solubility
Solubility is the mass of a solute which can dissolve in 100g of the solvent at a particular temperature to form a saturated solution
What affects the solubility of a solute
The temperature
Describe crystallisation
A saturated solution is cooled down, and the solid it can hold thus gets less. The solid that can no longer remain dissolved gradually appears as crystals
How does the speed of crystallisation affect the crystals formed
The slower the cooling process, the bigger and purer the crystals formed will be
