Flashcards
Science
Cards in this deck (78)
- 1Energy cannot be created or ________. It can only be ___________ from one form to another. (law of conservation of energy)destroyed
transformed - 2Where does a kettle get its energy from? What is the useful energy from a kettle?Electric
Heat - 3Current and Voltage is measured in ......Ampere (Amps)
Volts - 4What are the advantages of using a parallel circuit instead of a series circuit?If a wire in a parallel circuit breaks the component (bulb) will still work but it wouldn't in a series circuit.
- 5What is a fuse and what how does it work?A fuse is a safety device that prevents electrocution. When there is too much current flowing the fuse breaks down and melts, disconnecting the circuit.
- 6Which of the following three fruits generates the most electricity naturally and why? Potato Lemon OrangeLemon, because it has the most citric liquid.
- 7State 4 properties of metals.Any 4 from:
Strong
Ductile
Malleable
Solid
Shiny when clean
High melting and boiling points
Good conductor of heat and electricity
Dense Sonorous - 8State 3 uses of metalsMercury - thermometers
Copper - copper wire for electricity
Titanium - airplane bodies - 9The squeaky pop test is a test for what gas?Hydrogen
- 10What is needed for rusting to take place?Water and Oxygen
- 11The process of rusting is called oxidation while the chemical name for rusting is __________ ________iron oxide
- 12State the 3 ways in which rusting can be prevented.Greasing or oiling
Plating
Painting - 13Metal + Acid = ________ + __________Salt
Hydrogen - 14Sodium + sulfuric acid = ___ + ___Sodium sulfate
Hydrogen - 15State the reactivity series from potassium to gold.Potassium
Sodium
Calcium
Magnesium
Aluminium
Zinc
Iron
Lead
Copper
Silver
Gold - 16Copper compounds are _____blue
- 17Iron salts are pale green or _____brown
- 18Aluminium salts are white or colorless while calcium salts are _____white
- 19Do most metal carbonates dissolve in water?Yes, they do.
- 20Metal carbonate + acid = _______ + _______ + ________Salt
Carbon dioxide
Water - 21Define bases.Metal oxides, hydroxides and carbonates that are all alkali.
- 22Copper oxide + HCL = Copper hydroxide + HCL = Copper carbonate + HCL =Copper chloride + water
Copper chloride + water
Copper chloride + water + carbon dioxide - 23In what substance are Nitrogen, Potassium and Phosphate in?Fertilizers
- 24How can you make large copper sulfate crystals?By suspension. Suspend a small copper sulfate crystal in a concentrated copper II sulfate solution.
- 25Which salt is formed from the reaction of calcium with nitric acid?Calcium nitrate
- 26Which gas is formed when a metal carbonate reacts with acid?carbon dioxide
- 27What is the most reactive metal in the group one metals in the periodic table?Francium
- 28What is this test for? "Put a burning splint into a tube of the gas ( the gas will explode with a squeaky pop)Hydrogen gas
- 29Which of these is NOT a sign that a reaction has taken place? a. the substance catches fire b. the substance has changed from a solid to a liquid c. A gas is given off d. There is an explosionb
- 30In an experiment involving metals and its conduction of electricity which metals would have the greatest voltage? a. copper & copper b. zinc & copper c. zinc & zincb
- 31What would you get if copper sulfate and magnesium were reacted together (displacement reaction) and explain?magnesium sulfate and copper
Magnesium will displace copper from its sulfate since it is more reactive than copper. - 32Iron sulfate + copper =NO REACTION
- 33Define exothermic and endothermic reactions.Exothermic reaction - when heat is released
Endothermic reaction - when heat is absorbed - 34What is more reactive, copper or gold?Copper
- 35Complete combustion of carbon is when carbon is burnt in an excess supply of oxygen producing carbon dioxide and more energy. What is incomplete combustion of carbon?When carbon is burnt in a limited supply of oxygen producing carbon monoxide and less energy.
- 36If I burn a metal in air will its mass change? If so will it decrease or increase?Yes the mass will change and it will increase.
- 37What is combustion?When an element burns in air (to give an oxide).
- 38What needs to happen for this reaction to take place? Aluminium + iron oxide = Aluminium oxide + ironIt needs to be heated
- 39When magnesium is burnt, what happens?There will be a big white dazzling flame and the magnesium remains will turn white
- 40What sort of reaction is this? Potassium + oxygen = Potassium oxideOxidation
- 41Iron is unreactive in ________ and ________ but reacts in _______Water or Air in any order
Acid - 42Distance is = ? Speed is = ? Time is = ?Speed * time
Distance/time
Distance/speed - 43How long would it take a person to walk 10km if their average speed is 5.4km/h?10/5.4 = 1.85 hours
=1.85*60
=111 minutes - 44A car is travelling at a constant speed. Compare the forward and the backward forces.They would be the same.
- 45Give a more scientific term for increasing speed and decreasing speed.acceleration
deceleration - 46What is the formula for acceleration/deceleration (also include the words final and initial speed/time)?= final speed - initial speed
___________________________
final time - initial speed - 47A person first travels for 4 seconds, steadily increasing their speed to 6 m/s from 0 m/s. Then they maintain a constant speed for the next 6 seconds. After they steadily decrease their speed to rest in the last 4 seconds. Calculate the deceleration and acceleration rate (show working).Acceleration = 6-0/ 4-0 = 1.5 m/s (squared) deceleration = 0-6/ 14-10 = 1.5 m/s (squared)
- 48When there is a balanced force from the left and the right of an object, the object is either at _____ or maintains a _________ speed.rest
constant - 49A bicyclist streamlines her body. Why?Because then there is less air resistance acting on her from in front so the force pushing forward would be greater.
- 50A man on a parachute lands safely. Why?Because the parachute has a large surface area, there is a stronger air resistance force but the gravitational force however is stronger.
- 51Air resistance depends on the size, the _____ and the _____.Shape
Speed - 52Who discovered force? (Newtons)Issac Newton
- 53The Normal force (force applied at 90 degrees) per unit area is the definition of what term?Pressure
- 54Pressure = ? Force = ? Area = ?Force/Area
Pressure*Area
Force/Pressure - 55Pascal is = ?Newtons/meter squared
- 56Weight, a force, = ?mass*gravity
- 5710m/s squared is = what force?Gravity
- 58The ________ surface area the higher the pressure. Max pressure = Force/min Area Min pressure = Force/max Areasmaller
- 59Why do knives have a sharp edge?Because they are used to cut through something and if they have a small surface area at their point then less force can be applied and there will still be a high pressure.
- 60Why does a balloon expand (force)?When air is blown into a balloon a force is exerted on the molecules causing them to push the balloon walls thus forcing the balloon to expand.
- 61The ________ the altitude the ________ the atmospheric pressure.lower - higher
OR
higher - lower - 62Why do tractors have large tyres?This helps because the tractor would not get stuck in the soil since there is less pressure applied onto the soil because of the large surface area of the tyres
- 63Does pressure in liquids increase or decrease with depth?Increases with depth
- 64When I put a beaker on a strip of water nothing really happens but when I put a burning paper in the beaker then put it on a strip of water, the water outside of the beaker pushes the water inside the beaker. Why?At first the pressure is the same in and out the beaker but when the burning paper is put in the beaker oxygen is being used up thus creating a lower pressure inside the beaker and a higher pressure outside. The higher pressure outside pushes the water into the beaker.
- 65Define a momenta turning effect of a force at a fixed point (pivot)
- 66The larger the perpendicular distance form the pivot point and the bigger the force the ______ the turning point.larger
- 67Moment of a force = ? Unit for moment = ?Force * perpendicular distance form pivot
Newton meter (Nm) - 68A large force * a small distance = a ________ force * a _________ distancesmall
large - 69The force is 2N The perpendicular distance is 0.4m. What is the moment?2*0.4 = 0.8Nm
- 70Clockwise moment = _________ moment Balanced or not moving objectAnti-clockwise
- 71The larger the perpendicular distance from the pivot, the _____ force needed.less
- 72Why should you grip the handle bars of a bicycle at the ends?Because that would mean less force will be needed to turn or twist since the perpendicular distance is large so less force needed.
- 73Where is the center of gravity for uniform objects like a meter ruler?The center of the body
- 74What should I do if I want to stabilize an object? State the two factors.Put the object on a large surface area and make sure the center of gravity of the object is closer to the ground.
- 75How can an object be in an unstable equilibrium?When its center of mass / gravity is directly above the pivot point.
- 76Pressure in _________ = depth * density * gravityliquids
- 77When a car passes by, a person was pushed slightly towards the car. Why?A car runs by the engine which uses oxygen, so when the car passes by the person the oxygen on one side of him/her is taken in creating a low pressure thus making the higher pressure on his/her other side push the person towards the car.
- 78What does hydraulic fluid do?Hydraulic fluid is used in car brakes and multiplies the force and area but the pressure will be the same as the beginning.
e,g 10/2 = 5 ALSO 1000/200 = 5