Science 59 questions Flashcards
The _______ in rbc carry the oxygen
haemoglobin
Give the percentage of the gases (Inspired air)
Nitrogen
Oxygen
Carbon dioxide
Nitrogen: 78%
Oxygen: 21%
Carbon dioxide: 0.03%
Give the percentage of the gases (expired air)
Nitrogen
Oxygen
Carbon dioxide
Nitrogen: 78%
Oxygen: 16%
Carbon dioxide: 4%
Why are red blood cells are unusual cells
they do not have nucleus
Why most solutes dissolve faster in hot water than in cold water
in hot water, the particles have more energy, they move faster
Why did you use a line drawn in pencil on the ppaper chromatography
the pencil lead is insoluble in water, ink will effect the results
why is it important to not let the ink spot go under the water
the ink spot will dissolve in water instead of travel upwards if it is under water
in paper chromatography, the dye which treavels the furthest is the __ soluble in the solvent
most
what is hydrothermal vent
places where hot water from the sea bed rushes out into the water
why are there no plants at hydrothermal vent
no light and it is too hot
what is the producer at hydrothermal vent
bacteria
define ecosystem
a netwrok of interactions between all living organisms and non-living organisms around them
definine bioaccumulation
the increase of a toxic substance in an organims
define biomagnification
the increase of a toxic substance when going along a food chain from a lower leel to a higher level
what is microplastics
plastic that are less than 5mm long
what are the sources of microplastics
healthcare and beauty products, big pieces of plastic broken down
what is bioplastics
made form biomass resources
give the formula of pressure
pressure = force/area
give the formula of moment
force x distance (nm)
where did the early atmosphere get used up
phtosynthesis
trapped in fossil fuel
trapped in sedimentary rocks
the smaller the surface area of contact, the ________the pressure
larger
what is the law of reflection
angle of reflection = angle of incidence
a red car appears red under ______ light and ________ light
red and white
name the atomic model suggested by jj thompson
plum pudding model
what is a galaxy
made of stellar dust, gas, stars and solar systems held together by gravity
where is the asteroid belt located
mars and jupiter
to form haemoglobin, what are the nutrients needed
protein and iron
iron is important for making ______
haemoglobin
why do we need fiber in our diet
to prevent constipation
what substance found in cigarette which can lead to addiction
nicotine
what is a joint
a place where two bones meet
what attach muscles to bones
tendons
state the movement of ball and socket joint
circular
state the movement of hinge joint
back and forth, one direction
why do tendons not stretch
the bone cannot move
what is antagonistic muscles
a pair of muscles which work oppositelu
when you bend your arm, the biceps ___ while the tricep _______
contract, relax
during endothermic reaction, thermal energy is _______
absorb
explain why you get a fizzy feeling when you eat sherbet
carbon dioxide is produced
what is found in chemical ice pack
ammonium nitrate and water
function of chemical ice pack
reduce swelling
what is found in self heating can
calcium oxide and water
what is the formula for sherbet sweets
citric acit+sodium hydrgogencarbonate = sodium citrate+water+carbon dioxide
what is galvanizing
covering iron with zinc
why sodium and potassium must be stored under oil
to prevent it reacting with water vapour and oxygen in the air
write a word equation for the reaction between potassium and water
potassium hydroxide+hydrogen
write a word equation for the reaction between magnesium and water
magnesium oxide+hydrogen
the stronger the magnet, the ________ number of magnetic field lines
more
the stronger the magnet, the ______ the magnetic field lines
closer
the magnetic field lines start from ____ pole to ______ pole
north, south
3 ways to strngthen the electromagnet
add soft iron coil
increase number of coil
increase the currrent
suggest an application of electromagnet
doorbell
suggest one difference between permanent magnet and electromagnet
permanent magnet cannot switch on and off
why the reaction between magnesium and steam is more vigorous then the reaction between magnesium and water?
more energy move faster particls
difference between endothermic reaction and process
Endothermic reaction is a reaction which absobs heat from surroundings. (sherbet sweets)
Endothermic process also absorbs heat from energy, but no new products are formed. (ice melting)
