Science Revision YEAR 9.txt
Card Set Information
Science Revision YEAR 9.txt
year 9 science
3 ways to describe a solid?
1.The particles are arranged in regular patterns
2.They are held tightly together and cannot move
3.They move back and forward
3 ways to describe a LIQUID?
1.Particles arranged together, but not in a regular way
2.The particles are not so tightly held together as solids
3.The particles are able to flow and change places freely
3 ways to describe a GAS?
1. Particles are far apart from each other
2. They are not arranged in any particular way
3. Weak forces holding them together
What is dissolving?
It is the change when a solid mixes with a liquid to make a transparent solution
Why is dissolving useful?
In your blood, it carries food particles dissolved in it to all parts of your body.
What happens to solubility when a solution is heated up?
What is the name for substances that dissolve?
What is the name for substances that can't dissolve?
What is a solution?
A solution is a mixture (for example) of salt and water is clear, you cannot see the salt. It has dissolved.
The solid that dissolves in a liquid to form a solution
The liquid in which the solute dissolves in
What can dissolving be speeded up by?
What is solubility?
A measure of how much solute will dissolve in a set amount of solvent at a set temperature.
What is a saturated solution?
A saturated solution is a solution in which the solvent cannot dissolve any more solute to increase the concentration of the solution.
What are seperation techniques?
Processes used by scientists to obtain pure substances or to isolate them from other substances.
What is a mixture?
A mixture is made from different substances that are not chemically joined together.
What is a compound?
In a compound, two or more different elements are joined together chemically
What is an atom?
They are the simplest form of molecule. Made up of neutrons, protons and electrons.
What is a molecule?
Two or more atoms joined together
What is an element?
These contain the same type of atom. They cannot be split into simpler substances.
What is the filtrate?
The clear liquid that runs out of the filter.
What is the residue?
The solid that is left behind
What is evaporation?
Evaporation is the process by which water is converted from its liquid form to its vapor form. It is used to seperate a soluble solid from a liquid
What is condensation?
It is gas turning into liquid, usually as a result of cooling.
What is the name of two liquids that cannot mix?
What does hydrated mean?
Chemically combined with water
What is the test to see if something is water?
Add a few drops of liquid to Dehydrated Copper Sulphate. If it is water it will go from
What happens to Hydrated copper sulphate when heated to remove waste?
Examples of substances needing to be seperated for every day life use?
Copper- drink cans and pipes
Gold and silver- jewellrey and electronic circuits
Crude oil- plastic and fuels
What are the main seperation techniques?
5. Fractional Distillation
7. Seperating funnel
What is special about filter paper?
It has tiny holes in it that lets the liquid through but not the solid particles. It acts like a sieve
What is a suspension?
It is a mixture in which fine insoluble particles are suspended in a liquid and are held up by buoyancy (the ability to float)
What is the process to obtain pure salt from rock salt?
When would you use Evaporation and Crystallisation?
When the solid you want to obtain is soluble.
Liquids which do not mix are called Immiscible.
EG. Oil and vinegar or oil and water
How do you seperate immiscible liquids?
With a seperating funnel and gradually it will seperate
3 examples of immiscible liquids?
1. Oil and water
2. Oil and vinegar
3. Lava lamp
What is distillation used for?
Distillation is used for seperating the solvent from the solution.
How does Distillation work?
It works by the solvent evaporating, gas hits a condenser and then turns into a liquid.
Examples of when you might use distillation?
To seperate green colouring from green water
In distillation, which liquid remains in the flask?
The solvent with the higher boiling point
What is the boiling point of Ethanol?
When is Fractional Distillation used?
It is to seperate liquids if their boiling points are close together
What is the special piece of equiptment used in Fractional Distillation? What does it contain and why?
A fractionating column is used. It's usually packed with glass beads which increases the speed of condensation of the glasses
What industry uses Fractional Distillation?
The oil industry (crude oil)
What happens in the fractionating column?
The lower boiling point gases rise to the top (eg petrol) and can be extracted. The higher boiling point gases can be extracted at different points on the column.
Who created the Liebig Condenser?
Justus von Liebig
What is the method to see what pigments are present in different colourings?
What is the reason substances seperate in Chromatography?
Each substance travels through the solid at its own pace
What is the function of the Optic Nerve?
To Transfer visual information to the brain
What is the function of the Iris?
Controls light levels inside the eye
What is the function of the Cornea?
It helps shield the eye from germs and other harmful matters
What is the function of the Lens?
To change the focus of objects that are at different distances
What is the function of the Retina?
To receive light focused from the lens and convert it into neural signals to the brain
If one substance is more soluble than others in the solution, what happens?
It will tend to move quickly with the solvent and not stick to the paper until later than the others that are less soluble.
What are the seven components of a balanced diet?
What can lack of nutrients lead to?
Malnutrition and starvation
What is Protein needed for?
Growth, repair and maintenance of body cells.
What is Fat needed for?
Energy, protection and insulation
What is Carbs needed for?
If you dont take enough vitamins, what could happen?
VITAMIN C- scurvy
VITAMIN D- rickets
What are minerals needed for?
component of teeth and bones
What is Malnutrition?
It is when you do not eat a balanced diet.
What is Dietary Fibre needed for?
helps food move along digestive system
What is water needed for?
To keep us hydrated,transporting substances in blood cooling the body and chemical reactions
What is the reagent used for Sugar and what is the colour change?
Benedicts solution and blue-brick red
What is the reagent used for Starch and what is the colour change?
Iodine and yellow/brown-blue/black
What is the reagent used for Protein and what is the colour change?
Buiret and blue-purple
What is the reagent used for Fat and what is the colour change?
Alchohol and water and clear-milky white emulsion
How many teeth should an adult have?
What are the 3 parts in the structure of the tooth?
What is digestion?
Digestion is the physical and chemical breakdown of insoluble food into small, soluble molecules so they can be absorbed into the bloodstream
What is the production of energy?
5 steps of digestion?
What is Ingestion?
Taking food into the mouth where it is physically broken down to smaller lumps to be able to swallow it
What is Digestion?
Digestion is the process of breaking down large insoluble food molecules to soluble molecules, this happens in the mouth, stomach and small intestine
What is Absorption?
The process by which the soluble products pass across the wall of the small intestine and into the blood
What is Egestion?
Undigested food is eventually passed out of the body via the anus
Label the diagram of Digestive system.
Why does the stomach lining produce hydrochloric acid?
Kills bacteria taken in with the food
: what is a transverse wave? Give examples.
Wave vibrations are at 90 degrees to the direction of the energy of the wave.
Water and light waves.
: what is a longitudinal wave? Give examples.
Wave vibrations are in the same direction as the energy of the wave.
Earthquakes and sound waves.
Waves: what is the amplitude of a wave?
How "loud" it is. It's half the height from peak to trough.
Its units are metres.
Waves: what is the frequency of wave? What is it's units?
The number of waves or vibrations which pass a point in 1 second
Waves: what is meant by the speed of a wave? What is it's units?
Metres per second
Light and Shadows: Umbra and Penumbra?
Umbra:a dark shadow with sharp edges formed by a small light source
Penumbra:The fuzzy shadow that surrounds the dark centre.
Reactivity table: List all the metals in order of reactivity?
Will a high metal on the list react with a compound of a lower metal?
Will a low metal on the list react with a compound of a higher metal?