SCIENCE SUMMARY Flashcards
- What apparatus(s) uses accurately/ exactly?
pipette & burette
- What apparatus(s) uses approximately/ nearest?
measuring cylinder & beaker
- What is pipette rounded to?
(1dp): eg. 25.0cm(3)
- What is burette rounded to?
(2dp): eg. 25.00cm(3)
- What is measuring cylinder rounded to?
nearest cm(3)
- What is beaker rounded to?
approximate volume of 100cm(3) or 250cm(3).
- If gas is stated, what apparatus is used?
gas syringe.
- What apparatus is used to find mass?
mass balance
- What is definition of denser?
heavier than oxygen
- What delivery is used for denser?
downward delivery.
- What is the definition of less dense?
lighter than oxygen.
- What delivery is used for less dense?
upward delivery.
- What is considered a pure substance?
element/ compound.
- State the features of a pure substance
- has fixed bp & mp.
- chromatography: 1 spot.
- State the features of an impure/ mixture
- melts below mp/ over a range of temps.
- boils above bp/ over a range of temps.
- chromatography: >1 spot.
- State the purification analysis methods
- filtration.
- crystallization/ evaporation.
- simple distillation.
- fractional distillation.
- chromatography.
- What is the filtration technique?
separate insoluble from mixture.
- What is the crystallization/ evaporation technique?
separate soluble solid from mixture.
- What is the simple distillation technique?
separate liquid solvent from a mixture.
- What is the fractional distillation technique?
separate miscible liquids from different boiling points.
- Name all prefixes and their SI units
- Terameter: 10(12)m
- Gigameter: 10(9)m
- Megakelvin: 10(6)K
- Kilometer: 10(3)m
- centimeter: 10(-2)m
- millisecond: 10(-3)s
- microsecond: 10(-6)s
- nanosecond: 10(-9)s
- What are the four types of object measurements?
- size of an atom.
- size of a hair.
- size of radius of earth.
- size of diameter of earth.
- What are the object measurements?
- size of an atom: 10(-10)m
- size of a hair: 10(-4)m
- size of radius of earth: 10(6)m
- size of diameter of earth: 10(7)m
- Name the base units and their SI units
- electric current: ampere(A)
- temperature: kelvin(K)
- What are the instruments used to measure length and what are they used for?
- measuring ruler: height.
- digital calipers: diameter of bigger objects, eg. test tubes.
- micrometer screw gauge: diameter of smaller objects, eg. piece of thin wire.
- What is a period?
period = time for one oscillation
- State an example of a period
R->S->T->S->R
- What causes a longer period?
- longer period length.
- greater gravitational field strength.
- What is a scalar quantity?
has magnitude only
- What is a vector quantity?
has magnitude & direction
- What is distance?
the total length travelled.
- What is displacement?
the shortest distance between the start & end point.
- What is the SI unit for distance & displacement?
m
- What is the SI unit for speed & velocity?
m/s
- Formula for speed
distance/time
- Formula for velocity
displacement/time
- How to answer ticker tape question?
the object is moving at (constant/ increasing. decreasing) speed.
- SI unit for ticker tapes
s
- Formula for total time of ticker tape?
total time= seconds x no. of ticks.
first tick is not counted as t=0
- What is acceleration?
the rate of change in speed/ velocity in one second.
- SI unit for acceleration
m/s(2)
- Formula for acceleration
final speed-initial speed/time
- How to write deacceleration answer?
dont write ‘-‘ in the answer even though its a negative number but instead write ‘deaccelerates’ instead of ‘accelerates’.
- What is the SI unit for average speed?
m/s
- Formula for average speed?
total distance/total time
- SI unit of distance time graph
m/s
- Formula for distance time graph
distance/time
- distance time graph:
- steep=???
- less steep=???
- steep= increasing velocity.
- less steep= decreasing velocity.
- SI unit of speed time graph
m/s(2)
- How to calculate distance for speed time graph?
calculate the bottom area of the graph.
- How to calculate the bottom area of speed time graph if the bottom area is a triangle?
area of triangle= 1/2 x b x h.
- How to calculate the bottom area of speed time graph if the bottom area is a rectangle/square?
area of rectangle/square= b x h.
- speed time graph:
- steep=???
- less steep=???
- steep= increasing acceleration.
- less steep= decreasing acceleration.
- Do you need to calculate the speed in distance time graph?
no.
- How much is the acceleration in a vacuum?
10m/s(2)
- What is free fall?
a vacuum.
- If air resistance can be ignored on earth, how much is the acceleration?
10m/s(2)
- What is the change of state from solid to gas called?
sublimation
- What are the features of solids? (eg. arrangement, movement, forces, kinetic energy.)
-arrangement: particles are packed very closely together in an orderly arrangement.
- movement: particles vibrate about a fixed position and are not free to move.
- forces: particles are held together by strong forces.
- ke of particles: low.
- What are the features of liquids? (arrangement, movement, forces, kinetic energy.)
- arrangement: particles are packed close together but not in an orderly arrangement.
- movement: particles are able to slide over each other and move throughout the liquid.
- forces: particles are held together with weaker forces.
- ke of particles: higher.
- What are the features of gases? (arrangement, movement, forces, kinetic energy.)
- arrangement: particles are far apart in a random arrangement.
- movement: particles are free to move throughout the container or the space that the gas occupies.
- forces: force between particles is very weak or negligible.
- ke of particles: highest.
- Draw the heating curve and label the table
in diagram
- Draw the cooling curve and label the table
in diagram
- Describe what happens during melting or boiling
temperature remains constant during melting or boiling as the energy is being absorbed.
- Describe what happens during condensation or freezing
temperature remains constant during condensation and freezing as energy is being released.
- What is the atomic structure for proton?
- relative charge: +1
- relative mass: 1
- position: in the nucleus
- What is the atomic structure for neutron?
- relative charge: 0
- relative mass: 1
- position: in the nucleus
- What is the atomic structure for electron?
- relative charge: -1
- relative mass: 1/1840 = 0
- position: in electron shells
- What are the periodic table definitions?
- proton (atomic) number.
- nucleon (mass) number.
- isotopes.
- What is the definition of a proton (atomic) number?
the number of protons in the nucleus of an atom.
neutral atom: proton=electron
- What is the definition of a nucleon (mass) number
the number of neutrons and protons in the nucleus of an atom.
neutral atom: proton=electron
- How to find the number of atoms?
nucleon (mass) no. - proton (atomic) number.
- State the definition of isotopes
atoms of the same element with the same number of protons but different number of neutrons.
- What is the meaning of a group in the periodic table?
atoms of elements in the same group with the same number of valence electrons
- Is a group vertical or horizontal?
vertical (⏐).
- Is a period horizontal or vertical?
horizontal (━).
- What is the meaning of a period in the periodic table?
atoms of elements in the same period with the same number of electron shells
- State the definition of positive ions
atoms of metals (Grp 1-13) that lose electrons to form positively charged ions to achieve a stable electronic configuration.
- Will there be more protons or electrons after forming positively charged ions?
no. of protons > no. of electrons
the no. of protons will never be equal to the no. of electrons.
- State the definition of negative ions
atoms of non metals (Grp 15-17) gain electrons to form negatively charged ions to achieve a stable electronic configuration.
- Will there be more protons or electrons after forming positively charged ions?
no. of protons < no. of electrons
the no. of protons will never be equal to the no. of electrons.
- Does grp 18 elements lose or gain electrons?
grp 18 elements are chemically unreactive so they wont lose or gain electrons as their atoms already have a stable electronic configuration.
