Science of The House Flashcards
Which materials are good conductors of heat?
Metals
Which is the best conductor from Steel, Brass, Aluminium and Copper?
Copper
What is meant by conduction?
When heat travels through a material
What is everything made from?
Particles
Explain, in terms of particles, how heat is transferred in conduction.
Apply heat and the material gets hot. The particles in this part of the material start to vibrate as they gain energy. This vibration causes the particles next to them to vibrate and this passes the heat energy through the material.
What is meant by convection?
Heat moves through a liquid or a gas.
What is the term for heat moving through a liquid or a gas?
Convection
Explain, in terms of particles, how heat is transferred in convection.
Where liquid/gas is heated it gets hot. Particles gain energy, vibrate and move away from each other. Particles with most energy move up and their place is taken by particles with less energy. When particles cool they move down to be heated again. This continues until the whole gas or liquid is at the same temperature.
What is meant by radiation?
When heat is given out as waves from an object
What is the term for heat being given out as waves from an object?
Radiation
What is the other term used for heat?
Infrared
State three ways to reduce heat loss from a house.
Double/triple glazing, loft insulation, draught excluders, cavity wall insulation
What is current?
Charge passing a point per second
Which device measures current?
Ammeter
Which device measures voltage?
Voltmeter
What is the symbol for an ammeter?
Circle with an A in it.
What is the symbol for a voltmeter?
Circle with a V in it
How should an ammeter be connected to measure the current in a component?
It should be connected in series with the component
How should a voltmeter be connected to measure the voltage across a component?
It should be connected across the component
How can you identify a series circuit?
It is a circuit with only one path round it.
What happens if you unscrew one of the lamps in the circuit below? Why?
The other lamps go out. There is a break in the circuit and the current does not have a complete route to the battery.
How can a parallel circuit be identified?
It is a circuit with more than one path round it.
Which circuit component is represented by the following diagram?
Cell
Which circuit component is represented by the following diagram?
Switch
Which circuit component is represented by the following diagram?
Lamp
Which circuit component is represented by the following diagram?
Motor
Which circuit component is represented by the following diagram?
Resistor
Which circuit component is represented by the following diagram?
Variable Resistor
Which circuit component is represented by the following diagram?
Wire
Which circuit component is represented by the following diagram?
Buzzer
Which circuit component is represented by the following diagram?
Battery
What is the rule for current in a series circuit?
The current is the same everywhere
What is the rule for voltages in a series circuit?
The voltage across each component added together is equal to the supply voltage.
What is the rule for current in a parallel circuit?
The supply current is equal to the current in each branch added together.
What is the rule for voltages in a parallel circuit?
The voltage across each branch is equal to the supply voltage.
What is meant by a short circuit?
When there is a fault in a circuit that means the circuit has a lower resistance than it should.
State one cause of a short circuit.
- A loose screw across bare wires
- Solder coming loose and touching bare wires
- Wire coming loose touching another part of the circuit
Why is a short circuit dangerous?
There is a large current
What is the purpose of a fuse?
To protect the flex
Explain how a fuse works.
- A fault develops meaning that there is a high current
- The wire in the fuse gets hot and melts
- This creates a break in the circuit
Are house lights wired in series or parallel?
Parallel
Why are house lights wired in parallel?
So if one breaks the others will stay on.
Name the 5 types of mictoorganisms
- Fungi
- Protozoa
- Algae
- Bacteria
- Viruses
What type of microorganism is yeast?
Fungus
What do we use yeast to make?
- Bread
- Alcohol
Which microorganism is used to make bread and alcohol?
Yeast (Fungus)
Which microorganism is used to make yoghurt?
Bacteria
What two conditions do microorganisms need to grow well?
- Nutrients(food)
- Warmth
How can you remove microorganisms from your skin?
Wash your hands with soap and water.
Name 2 common household acids.
- Vinegar
- Fizzy juice
- Lemon juice
- Fruit juice
Name 2 household alkalis.
- Oven Cleaner
- Soap
- Toothpaste
What colour is litmus blue in an acid?
Red
What colour is litmus blue in an alkali?
Blue
What colour is litmus blue in a neutral substance?
Blue
What colour is litmus red in an acid?
Red
What colour is litmus red in alkali?
Blue
What colour is litmus red in a neutral substance?
Red
What type of substance does litmus red identify?
Alkali
What type of substance does litmus blue identify?
Acid
What colour does phenolphthalein go in acid?
Stays clear
What colour does phenolphthalein go in alkali?
Pink
What colour is phenolphthalein in neutral substances?
Clear
What colour is universal indicator in acid?
Red
What colour is universal indicator in alkali?
Purple / Blue
What colour is universal indicator in a neutral substance?
Green
Which pH numbers are acidic?
pH1 - pH 6
Which pH numbers are alkaline?
pH 8 - 14
Which pH number is neutral?
pH 7
What is the advantage of using universal indicator?
It can identify acids and alkalis and their strength
What is the pH of a weak acid?
pH 6
What is the pH of a strong acid?
pH 1
What is the pH of a weak alkali?
pH 8
What is the pH of a strong alkali?
pH 14
How are particles arranged in a solid?
In rows and columns
How are particles arranged in a liquid?
Close together but jumbled
How are particles arranged in a gas?
Far apart and moving
What is voltage?
A measure of the energy transferred by the charge
State the energy change in a lamp.
Electrical energy to light energy
State the energy change in a motor.
Electrical energy to kinetic energy
State the energy change in a buzzer.
Electrical energy to sound energy.
State the energy change in a cell or battery.
Chemical energy to electrical energy.
State 2 places a variable resistor could be used.
- light dimmer switch,
- volume control,
- brightness control,
- speed control on a Scalextric car
What components do you need to make a continuity tester?
- Battery or cell
- Lamp
- 3 wires
Explain how a continuity tester works.
A battery is connected in series with a lamp, but a gap is left in the circuit. The device being tested is placed in the gap - if the lamp lights the component is ok, if the lamp does not light then the device is broken.
Describe an advantage of having two lamps connected in parallel.
If one lamp breaks the other will remain lit as it still has a complete route to the battery.
State the word equation for making alcohol.
Sugar + Yeast → Alcohol + Carbon Dioxide
Explain how heating food until it is piping hot helps to keep it safe.
The microbes need nutrients and warmth to grow, by making it piping hot it is too hot for the microbes and they are killed. So the food contains less microbes.
Explain how putting food in a fridge helps to keep it safe.
The microbes need nutrients and warmth to grow, the fridge is cold so the microbes cannot grow. So there are less microbes on the food.
State the what is meant by an indicator.
A chemical that produces a colour change in acids or alkalis.
Name the acid that is in vinegar.
Ethanoic acid
Name this piece of science equipment.
Conical flask
Name this piece of science equipment.
Burette
Name two types of pollution that contribute to acid rain.
- Burning fossil fuels
- Vehicle fumes from exhausts
Name two gases that contribute to acid rain.
- Sulphor dioxide
- Nitrogen oxides
State a effect of acid rain on stone or metal structures.
- Stone starts to dissolve.
- Metals will corrode (rust)
The the gas produced when an acid reacts with a metal.
Hydrogen
State the test for hydrogen gas.
Burns with a squeaky pop.
As copper is a good conductor of heat, suggest a use for it.
- pans
- water pipes
- radiator pipes
