Force and Energy
Heat and Applications
Chemical Changes
Ecosystems
Electrical Systems
100
What are the type of forces
Contact and Non Contact
100
3 Heat Processes
Conduction
Convection
Radiation
100
How to identify whether a substance undergo CHEMICAL or PHYSICAL change
Chemical:
1. New Substances formed
2. Irreversible
Physical:
1. NO new substances formed
2. Often reversible
100
Trophic Levels of food chain
Producer
Primary Consumer
Secondary Consumer
Tertiary Consumer
100
Formula of V
V=RI
200
Formula of Weight and its S.I units
Weight= Mass x Gravitational Force (mg)
S.I unit: N (Newton)
200
How is heat transferred via Convection
1. Water gain heat from nearby heat source
2. Expand & Density decrease, water rises
3. Cooler water on top with higher density sinks
4. Cool water gain heat and density decreases
5. Convection Current forms, process repeats
200
Combustion (Chemical/Physical)
Thermal Decomposition (Chemical/Physical)
Oxidation (Chemical/Physical)
Melting (Chemical/Physical)
Combustion (Chemical)
Thermal Decomposition (Chemical)
Oxidation (Chemical)
Melting (Physical)
200
Relationships between organisms and what about it [3 Relationships]
Bonus: if you can identify another relationship
1. Predator-Prey (One species kills and consumes the other species)
2. Parasitism (One species gains benefits from another species by causing harm to the host)
3. Mutualism (Both organisms that benefit each other)
Bonus: Commensalism (One species gains benefit from another species without causing harmful effect on the host)
200
How to calculate cost of energy consumption [2 steps]
1. Find energy consumption
Power (kW) x Time (h)= kWh
2. Find cost
Energy (kWh) x Unit Cost ($/kWh)= $
300
Types of Energy and its definition
Renewable: Energy Sources that can be replenished in a short period of time (E.g. Wind, Biomass, Solar, Hydroelectric)
Non-Renewable : Energy Sources that are limited and cannot be replenished in a short period of time (E.g. Fossil Fuel)
300
How is heat transferred via conduction
1. Region of medium gain heat and particles expand and vibrate faster
2. Vibrating particles COLLIDE with neighboring particles, transferring the heat energy.
3. Process repeats till whole medium gains heat via conduction.
300
2 Properties of Acids
2 Properties of Alkali
Acid
1. Sour
2. Corrosive when Concentrated
3. Turn blue litmus paper red
Alkali:
1. Soapy
2. Corrosive when Concentrated
3. Turn red litmus paper blue
300
What is the main source of energy in an ecosystem?
SUN
(Reject: Food made by producers)
300
Definition of Current, S.I unit, and how to measure
Definition: Rate at which electric charges flow
S.I unit: A (Ampere)
S.I symbol: I
Measure: Ammeter, connected in series
400
Laws of Conservation of Energy
1. Energy cannot be created or destroyed
2. Energy can only be converted to other forms of energy
400
1. Methods of radiation [3 methods]
2. Factors affecting radiation
1. Emitter & Absorber & Reflector
2. Colour & Texture & Surface Area
400
What are the two tests for CO2(g) and H2(g)
CO2(g):
Bubble CO2 into limewater, White precipitate formed
H2(g):
Use a lighted Splint, it should extinguish with a "pop" sound
400
How many % of energy is transferred from one trophic level to the next?
How many % of energy lost and via what?
10% transferred
90% lost via
- Respiration
- Excretion
-Removal of faeces
400
Definition of Potential Difference, S.I unit, and how to measure
Definition: Amount of energy needed to push a unit charge of electric charges to flow between one point to another in a circuit.
S.I unit: V (Volt)
Measure: Voltmeter, connected in parallel
500
Definition, formulas, and S.I unit of Work Done and Pressure
1. Work done: Transfer of Energy
Formula: Force x Distance [S.I Unit: J, Joules]
2. Pressure: Force per unit Area
Formulas: F(N)/A(m3) [S.I Unit: Pa, Pascal]
500
What are the parts of a thermal flask that keeps hot water hot? [Clue: 2-3parts]
And how it keep hot?
Vacuum: Prevents conduction and convection rom occurring, heat loss via conduction and convection cannot occur
Silver lining walls: Good reflector of heat, reflect heat back to water, prevent heat loss via reflection
Air trapped b/w outer and inner walls: Air is a poor conductor of heat, reduce rate of heat loss via conduction.
500
What type reactions do acids undergo?
(Include reactants and products) and (Special reaction name)
Metal+Acid-->H2(g) + Salt
Carbonate+Acid-->CO2(g) + H2O(l) + Salt
Alkali+Acid--> H2O(l)+ Salt [Neutralisation]
500
Ways to Conserve the Environment and how it conserves the environment
1. Reduce D_____________
2. Any other valid reasons
1. Reduce Deforestation (Increase Carbon absorption for photosynthesis, decrease levels of CO2 gas)
2. Reduce land/water pollution + valid reason
3. Do not over hunt animals + Valid reason
4. Recycle Resources + Valid reason
500
Definition of resistance, S.I unit, how to VARY it
VARY: 2 types of resistors and factors
Definition: Opposition to the flow of electric charges.
S.I unit: Ω (Ohm)
Types of Resistors: Fixed & Variable Resistor
Factors: Length and Thickness