End of Year Ministry Exam (Science) Flashcards
An atom is made up of…
- positively charged protons
- negatively charged electrons
- neutrally charged neutrons
In energy levels, the first shell can hold a maximum of how many electrons?
2 electrons
In energy levels, the second shell can hold a maximum of how many electrons?
8 electrons
In energy levels, the third shell can hold a maximum of how many electrons?
8 electrons
How do you find the number of protons and electrons in an atom?
the atomic number
What is the name of Group 1?
alkali metals
What is the name of Group 2?
alkaline earth metals
What is the name of Group 7?
halogens
What is the name of Group 8?
inert/noble gases
What do elements in the same group have in common?
they all have the same number of valence electrons
What do elements in the same period have in common?
they all have the same number of electron shells
What are ions?
atoms with a positive or negative charge
This is not a question just make sure to remember this…
Giving and taking electrons:
Group 1 - give away 1 (+1)
Group 2 - give away 2 (+2)
Group 3 - give away 3 (+3)
Group 4 - share with other atoms
Group 5 - take 3 (-3)
Group 6 - take 2 (-2)
Group 7 - take 1 (-1)
Group 8 - none (already stable)
REMEMBER ALL ELEMENTS WITHIN A GROUP FORM IONS WITH THE SAME CHARGE
Ions that lose electrons become _______ charged.
positively
Ions that gain electrons become _______ charged.
negatively
What is the formula for ppm?
1 ppm = 1g of solute/1000000g of solution
What is an electrolyte?
A substance that dissociates into ions when dissolved in water, since they create solutions that conduct electricity.
Ex. HCI, NaOH and NaCl
Electrolytes create…
Acidic, basic and salt solutions
Non-electrolytes create…
Molecular solutions
Which of the following solutions is slightly basic?
Sea water (pH 8), Coffee (pH 5.5) or Gastric juice (pH 2)
Sea water
Which of the following solutions has the highest concentration of H+ ions?
Sea water (ph 8), Coffee (pH 5.5) or Gastric juice (pH 2)
Gastric juice
A truck drives down a highway. The truck tips over and highly acidic liquid leaks out. What should they do to neutralize it?
Add base to the spill
Fill in the blank:
HCl + NaOH —> ______ + H2O
NaCl
Fill in the blank:
2HCl + Ca(OH)2 –> ______ + 2H2O
CaCl2
Describe photosynthesis
Green plants with sunlight and water, remove carbon dioxide and use it to make food (sugar, glucose, oxygen)
Reaction: 6CO2 + 6H2O + sun energy —> C6H12O6 + 6O2
Describe cellular respiration
Cells use oxygen and glucose to make energy (ATP), releasing carbon dioxide back into the atmosphere
the reaction is basically the opposite of photosynthesis im too lazy to write the reaction down
Describe combustion
It is when a fire is created. CO2 and H2O always have to be on the product side
Equation: Fuel + Oxygen —> Carbon Dioxide + Water + Heat
Remember the triangle with fuel, heat and oxygen
Oxygen: Oxidizing agent
Heat: Ignition temperature
Describe oxidation
At least one oxygen atom and at least one other element
Reaction: 4Fe + 3O2 —> 2Fe2O3
What is needed in an acid-base neutralization equation?
Acid + Base —> Salt + Water
When two materials are rubbed together, what transfers from one object to another?
Electrons
When two materials are rubbed together the material thats looses electrons becomes…
Positively charged
What is the formula to solve for current?
I = Q/t
If the current of a circuit is 0.5 A, 20C of charge pass a point in the circuit every ______ seconds.
Answer: 40 seconds
What is the formula for Ohm’s law?
I = V/R or V = (I)(R)
What is the current in the circuit with 100V and 200 ohms?
Answer: 0.5 Amperes (A)
What is the voltage of the battery with 5 ohms and 3A?
Answer: 15 Volts (V)
The sodium concentration in a bottle of mineral water is 0.005% (m/V). What is the sodium concentration of this mineral water in ppm?
Answer: 50 ppm
What are the two formulas for power?
P = E/t and P = (V)(I)
A 200W light bulb is turned on for 5 seconds. How much energy was used by the light bulb?
Answer: 1000 J or 1kJ
A 1kW light bulb is turned on for 40 seconds. How much energy was used by the light bulb?
Answer: 40 000 J or 40 kJ
A hair dresser’s 2kW blow dryer is used for 3 hours on a given day. How much energy was used by the blow dryer?
Answer: 21 600 000 J or 21 600 kJ or 21.6 mJ
Magnets contain the elements…
Iron, Cobalt and/or Nickel
What is the difference between a non-magnetic substance and a magnetic substance?
The electrons of non-magnetic substances rotate in opposite directions whereas the electrons of magnetic substances rotate in one direction
If 2 magnets are placed next to each other, the magnetic field lines will point ______ of the north and ______ the south
OUT of the north and INTO the south
Name the pros and cons of Fossil Fuels
Pros:
- Efficiency
- Cheap
Cons:
- Non-renewable
- Pollutions which causes greenhouse gases to increase
Name the pros and cons of Nuclear Energy
Pros:
- No greenhouse gases produced
- Renewable (for exam)
Cons:
- Radioactive waste if there was an accident
Name the pros and cons of Geothermal Energy
Pros:
- No greenhouse gases released
- Renewable
Cons:
- Only available in certain locations
Name the pros and cons of Hydroelectric Energy
Pros:
- Renewable
- No greenhouse gases
Cons:
- Creation of reservoirs at dam sites requires flooding of forests
- Can’t use it in many areas
Name the pros and cons of Wind Energy
Pros:
- Renewable
- No GHG emitted
- Non-polluting
Cons:
- Unpredictable
- Cannot be stored
- Unsightly
Name the pros and cons of Solar Energy
Pros:
- Renewable
- No GHG emitted
- Non-polluting
Cons:
- Unpredictable
- Expensive to set up
Name the layers of soil
- Organic matter
- Topsoil
- Subsoil
- Fragment parent rock
- Parent rock
What is permafrost?
Ground that has been frozen for at least two years. Found in polar regions and at high altitudes
What is the name of the layer above permafrost and the name of the layer below?
Layer above: Active layer
Layer below: Methane gas (CH4) trapped beneath permafrost
What are the consequences of permafrost if it melted?
- Structures built on the active layer can collapse because the permafrost can eventually melt which would make the ground shift
- When permafrost starts to melt the methane gas that was trapped will be released. This can break the ozone layer
What are watersheds?
An area of land whose lakes and rivers all empty into the same larger body of water
What are the three layers of the ocean?
Mixed layer: <200m, heated by sunlight
Thermocline: >200m, no solar energy, cold transition zone
Deep water: >1000m, cold and very dark, temperature does not change much
What is salinity?
A measure of the amount of salt dissolving in a liquid
Salinity is measured in g/1000ml or g/L
What are surface currents?
- They are caused by the winds
- Move horizontally
- Found in the 400m of water below surface
What is pack ice?
- Ice floating on the oceans near the north and south poles
- Expands and contracts with the seasons
- Formed from the upper layer of water freezing on contact with cold air
What are glaciers?
- A mass of ice on land
- They are not floating on water
- Glacier water is not saline
What are environmental impacts of melting glaciers?
- Sea level rises
- Thawing of ice
What is the cryosphere?
Consists of all the frozen water on earth’s surface
What is the thermohaline circulation?
Thermohaline circulation is a big ocean current system that moves warm and cold water around the world. It’s like a giant conveyor belt in the ocean that helps distribute heat and regulate climate. Warm water moves towards the poles at the surface, where it gets colder and sinks deep down. Then, it travels back towards the equator as deep, cold water. This circulation is important for balancing temperatures and keeping our climate stable.
Describe elastic deformation
A temporary change in the shape or dimensions of the material. When constraint is removed, the material returns back to its original shape
Describe plastic deformation
A permanent change in the shape or size of the material. Deforms and stays deformed
Describe fracture deformation
The material breaks
Name the 5 constraints
Compression, Tension, Deflection, Torsion and Shear
Describe hardness
Resists being scratched or deformed
Describe malleability
Deforms under compression, flattens
Describe ductility
Deforms under tension, stretches
Describe elasticity
Returns to its original shape after the stress
Describe plasticity
Does not return to its original shape after the stress. Can be shaped
What are characteristics of metals?
- Shiny substances
- Electrical conductivity
- High heat conductivity
What are characteristics of ceramics?
- Low or no electrical conductivity
- Sometimes thermal conductivity
- High hardness
- High heat resistance
- High corrosion resistance
- Low resilience
There is more but these are the main ones
What are characteristics of thermoplastics?
- No electrical conductivity
- Low thermal conductivity
- Sometimes hardness
- Sometimes heat resistant
- High corrosion resistance
- High resilience
What are characteristics of thermosetting plastics?
- No electrical conductivity
- Sometimes thermal conductivity
- High hardness
- High heat resistance
- High corrosion resistance
- High resilience
What is the formula for calculating speed changes?
(Size of A) (Speed of A) = (Size of B) (Speed of B)
What are the three types of motion?
- Rotational
- Translational
- Helical
What is the driver?
Receives the force that makes the mechanism move
What is the driven?
Moves as a result of the driver component’s motion
What is the intermediate?
Transmits the driver’s motion to the driven component (may or may not be present)
Define reversible
The driver component can become the driven component (and vice-versa)
Name the motion transmission systems
- Gear train
- Friction gear
- Chain and sprocket
- Belt and pulley
- Worm and worm gear
Name the motion transformation systems
- Rack and pinion
- Slider crank
- Cam and follower
- Screw gear
Of all the systems, which ones are non-reversible?
- Worm and worm gear
- Cam and follower
- Screw gear
What is a link?
Connects two or more parts in the same object
What is a direct link and an indirect link?
Direct link: Two parts are held together without any other part
Indirect link: Two parts are held together by another part (linking component)
What is a complete link and a partial link?
Complete link: Parts cannot move indepently
Partial link: Parts can move independently
What is a removable link and a non-removable link?
Removable link: Parts can be separated without damage
Non-removable: Parts become damaged if seperated
What is a rigid link and an elastic link?
Rigid link: Neither the linking components nor the surfaces of the parts held together can deform
Elastic/Flexible link: Either the linking components or the surfaces of the parts held together can deform
What is a guiding control?
Enable components to move with translational or rotational motion
