States of Matter (pg 120) Flashcards
What are the Three States of Matter?
Solid, Liquid and Gas (Materials come in these three forms)
Which state something is at a certain temperature (solid, liquid or gas) depends on how strong the forces of attraction are between the particles of the material.
How strong the forces are regarding the three states of matter depends on what three things?
a) the material (the structure of the substance and the type of bonds holding the particles together)
b) the temperature
c) the pressure
What is the model called to explain how the particles in a material behave in each of the three states of matter?
The model is called ‘Particle Theory’
by considering each particle as a small, solid, inelastic sphere
(the particles could be atoms, ions of molecules
What are ‘solids’ regarding The Three States of Matter?
1) In solids, there are STRONG FORCES of attraction between particles, which holds them close toether in fixed positions to form a very regular lattice arrangement.
2) The particles DONT MOVE from their positions, so all solids keep a definite shape and volume, and don’t flow like liquids.
3) The particles VIBRATE about their positions - the hotter the solids become, the more they vibrate (causing solids to expand slightly when heated)
see diagram on page 120
What are LIQUIDS regarding ‘the three states of matter?
1) in Liquids, there’s a WEAK FORCE of attraction between the particles, they’re randomly arranged and FREE to move past each other, but the tend to stick closely together.
2) Liquids have a definate volume but DONT keep a definate shape, and will flow to fill the bottom of a container.
3) The particles are constantly moving with random motion. the hotter the liquid gets, the FASTER they move. This causes liquids to expand slightly when heated.
see diagram on page 120
What are GASSES regarding ‘the three states of matter’?
1) In gasses, the force of attraction between the particles is very weak - they’re free to move and are FAR APART. The particles in gasses travel in STRAIGHT LINES.
2) Gasses DONT keep a deinate shape of volume and will always fill any container.
3) The particles more CONSTENTLY with RANDOM MOTION. The hotter te gas gets, the FASTER they move. Gasses either expand when heated, or their pressure increases.
see diagram on page 120
Particle Theory is a great model for explaining the three states of matter, but it isn’t perfect. why is this?
In reality, the particles aren’t solid or inelastic and they aren’t spheres - they are atoms, ions or molecules. Also, the model doesnt show the forces between the particles, so there’s no way of knowing how strong they are.
What does inelastic mean?
not elastic, (not flexible, slow to react or respond to chaging conditions)
What is meant by ‘State symbols’?
state symbols tell you the state if a substance in an equation.
eg;
(s) solid
(l) liquid
(g) gas
(aq) aqueous (dissolved in water)
page 99 tells you how a chemical reaction can be shown using a word equation, or symbol equation. Symbol equations can also include ‘state symbols’ next to each substance - they tell you what PHYSICAL STATE the reactants and products are in.
