Notes

SCIENCE EXAM PREP
atoms-basic building blocks of matter
element-a substance that is only made from one type of atom. a group of atoms [anything on the periodic table]
GOLDEN SYMBOL= [Au]
atomic number is always the smallest number
mass number is always the biggest number
METAL AND NON-METALS
carbon- non-metals
magnesium-non-metals
aluminum- metal
silicon-metal
phosphorus-metal
oxygen-metal
sulfur-metal
calcium-non-metal
sodium-non- metal
ELECTRON CONFIGURATION
1ST SHELL:2 ELECTRON MAX
2ND SHELL:8 ELECTRON MAX
3RD SHELL:8 ELECTRON MAX
4TH SHELL:16 ELECTRON MAX
WHAT IS FOSSIL FUEL?
oil, coal and gas
FORMING OIL AND GAS??
when sea creatures were squashed beneath sand. they can't rot and this turns them into oil and gas
solid- coal
liquid- oil
gas- gas
SEPERATION TECHNIQUES
FILTARATION: solid from liquid [ uses filter paper and funnel, solid gets trapped in filter paper and liquid passes through]
CRYSTALLISATION: solid dissolved in a liquid [ solution is heated until the liquid is evaporated. the salt is left behind]
CHROMATOGRAPHY: mixture of liquid [ used to figure out, what substance is present]
DISTILLATION: mixture of liquids with different boiling points [ different chemicals have different boiling points; we can use this to separate them]
HYPOTHESIS: GUESS TO AN ANSWER
AIM: TO FIND OUT WHAT WILL HAPPEN
PH SCALE.
ACID
-taste sour
-ph lower than 7
-turns blue litmus paper red
-red litmus paper stays red
-universal indicator
red/orange/yellow
BASE.
-taste bitter
-ph above 7
-turns red litmus blue
-blue litmus paper stays blue
-feels slippery
-universal indicator
blue/purple
NEUTRAL.
-ph7
-water
-universal indicator
green
NEUTRALISATION REACTION
acid+base>salt+water
hydrochloric acid+sodium>sodium+water
hydrochloric acid and sodium [ hydroxide]
sodium and water [ chloride]
chemical formula: [HCI+NaOH]
acid can produce= hydrogen iron
base can produce= hydroxide iron
ELEMENTS AND COMPOUNDS
-elements are substances that are made up of one atom
-compounds are chemically combined together to make a substance
CHEMICAL REACTION
- chemical reaction is the change of one substance into another substance
OBSERVATION FOR CHEMICAL CHANGE
-the color change
-energy may be produced [ burning/ fizzing]
-change in temperature
-a smell being produced
GENERAL CHEMICAL RECTION EQUATION
-chemical reactions are often represented by equation. these equations give information about the reaction in a simplified way
FIRE TRIANGLE
-oxygen
-fuel
-heat
COMBUSTION REACTION
metal plus oxygen = metal oxide
which means, element plus element = compound
GENERAL EQUATION
-when a chemical equation is written using common terms it is named a general equation.
WORD EQUATION
-when a reaction is written using the names of chemical substances, it is known as a word equation.
BURNING FUEL FOR ENERGY
-natural gas = last for 50 years
-oil = will run out between 2025 and 2070
-coal = when the other two fossil fuel finish than the quantity of coal will increase
WHAT MAKES OIL AND GAS SUCH, CONVENIENT SOURCES OF ENERGY
-energy dense
-efficient
-low in transformation cost
-affordable
-transportable
-delivers immediate power
-provides constant power
RENEWABLE ENERGY SUPPLIES
WHAT IS RENEWABLE ENERGY? are sources that are produced which never run out
GIVE THE 5 COMMON SOURCES OF ENERGY? solar/wind/hydro/geothermal/biomass
GIVE 2 BENEFITS OF RENEWABLE ENERGY? can reduce pollution/ reliable source power [never run out]
GIVE 2 DISADVANTAGES OF RENEWABLE ENERGY? difficult to generate wind and solar power because it needs wind to blow and sun to generate power
SOLAR, source: sunlight harnessed using solar panel or photovoltaic cells
advantage: renewable, abundant and inexhaustible energy source
disadvantage: space requirement, large areas needed for solar farms
WIND, source: wind harnessed using turbines that convert kinetic energy into electricity
advantage: renewable, harnesses natural wind patterns which are abundant
disadvantage: impact on wildlife: potential harm to birds and bats
TIDAL WAVE, source: energy generated from the movement of tides and waves
advantage: often less visually intrusive then wind farm
disadvantage: can affect marine ecosystem
BIOMASS, source: organic materials [ plants and animals waste] coverts into energy through combustion or other processes
advantages: can be converted into electricity, heat or biofuels
disadvantage: burning biomass can produce emission, affecting air quality
GEOTHERMAL, source: heat from the earth's interior harnessed for electricity generation or direct heating
advantage: provides a constant energy source, unaffected by weather conditions
disadvantage: potential for small earthquakes for small region
THE DIFFERENCE BETWEEN ACCURACY AND RELIABILITY?
-if all our values are altogether there is reliability, but it is not closer to the accuracy
-if all our values are closer to the true value it is accuracy
ANOMALOUS-different from what is usual or expected/ not fitting into a common or familiar type
DEFINITIONS:
RELIABLE-when the recorded results are close together and the data is repeatable.
ACCURATE- when the recorded results are close to the true value.
ANOMALOUS- when a data point does not fit with the other data point
[NEUTRALISATION OF ACID]
AIM- how much is needed to neutralize acid
HTPOTHESIS- t think that the acid will neutralize the acid depending on the concentration of the acid
EQUIPMENT:
-test tube/boiling tube
- test tube rack
-pipette
-measuring cylinder 10ml
-1.0 mol/l hydrochloric acid/2ml
-1.0 mol/l sodium hydroxide
-universal indicator
METHOD:
1st step: gather all the equipment which are required
2nd step: measure 2ml of hydrochloric acid using 10ml measuring cylinder
3rd step: transfer acid solution in the test tube/boiling tube
4th step: add two drops of universal indicator to the acid solution
5th step: record the color and the ph level
6th step: add sodium hydroxide, drop wise
7th step: record the number of drops
8th step: continue adding sodium hydroxide unless solution turns green
9th step: record the number of drops added to turn the solution green
10th step: clean all the equipment's and place them in their allocated places
DEFINITIONS
DECOMPOSITION- to separate a thing into its parts or into simpler compounds
PHOTOSYNTHESIS- a chemical process that occurs in plants, algae, and some types of bacteria, when they are exposed to sunlight
RESPIRATION- a process by which organisms exchange gases, especially oxygen and carbon-dioxide, with the environment.
COMBUSTION- the process of burning something
FOSSIL FUEL- an energy source formed in the earth's crust from decaying organic materials
PLANTS- a living thing that grows on earth and has a stem leave and root
ANIMALS- a living thing thar can move and eat and react to the world through its senses, especially of sight and hearing
FACTORIES- a building or set of buildings for manufacturing
OCEANS- the whole body of salt water that covers nearly three fourth of the surface of the earth
CO2 PRODUCTION- the process by which carbon dioxide is created, which can occur through natural, or human caused processes
CO2 ABSORPTION- a method for removing co2 from gas streams using a liquid solvent
O2 PRODUCTION- the process of creating oxygen
O2 ABSORPTION- the process by which oxygen it taken into the body and diffused into the blood stream
{ELECRICITY}
STATIC VS CURRENT
STRATIC- not moving
CURRENT- moving
WHAT IS MATTER MADE UP OF? matter is made up of tiny particles called atoms and molecules
WHAT GIVES ELECTRONS ENOUGH ENERGY TO LEAVE THEIR ATOM? this is known as excitation, and when electrons move up an energy level they are said to be in an excited state if the electrons gain enough energy to be removed from the atom entirely, this is known as ionization
IF SOMETHING HAS MORE PROTONS THAN ELECTRONS, WHAT CHARGE DOES IT HAVE? it has a positive charge
A BUILD UP OF CHARGE, THAT DOES NOT MOVE [ STATIC ELECTRICITY]
ELECTRIC CURRENT THE FLOW OF ELECTRONS.
-to do so we need energy [ battery or power [pack] pathway[power] and component[bulb].
SERIES CIRCUIT- connected one after another
PARALLEL CIRCUIT- are connected but goes through every element
-Current is the same everywhere in a series circuit
-The sum of the voltage of all components in the circuit is equal to the power supply
CONDUCTOR- e.g. metal [allow the electric current to flow]
INSULATOR- [ does not allow electric current to flow]