Science 59 questions

Question 1

The _______ in rbc carry the oxygen

Answer 1

haemoglobin

Question 2

Give the percentage of the gases (Inspired air)
Nitrogen
Oxygen
Carbon dioxide

Answer 2

Nitrogen: 78%
Oxygen: 21%
Carbon dioxide: 0.03%

Question 3

Give the percentage of the gases (expired air)
Nitrogen
Oxygen
Carbon dioxide

Answer 3

Nitrogen: 78%
Oxygen: 16%
Carbon dioxide: 4%

Question 4

Why are red blood cells are unusual cells

Answer 4

they do not have nucleus

Question 5

Why most solutes dissolve faster in hot water than in cold water

Answer 5

in hot water, the particles have more energy, they move faster

Question 6

Why did you use a line drawn in pencil on the ppaper chromatography

Answer 6

the pencil lead is insoluble in water, ink will effect the results

Question 7

why is it important to not let the ink spot go under the water

Answer 7

the ink spot will dissolve in water instead of travel upwards if it is under water

Question 8

in paper chromatography, the dye which treavels the furthest is the __ soluble in the solvent

Answer 8

most

Question 9

what is hydrothermal vent

Answer 9

places where hot water from the sea bed rushes out into the water

Question 10

why are there no plants at hydrothermal vent

Answer 10

no light and it is too hot

Question 11

what is the producer at hydrothermal vent

Answer 11

bacteria

Question 11

define ecosystem

Answer 11

a netwrok of interactions between all living organisms and non-living organisms around them

Question 12

definine bioaccumulation

Answer 12

the increase of a toxic substance in an organims

Question 13

define biomagnification

Answer 13

the increase of a toxic substance when going along a food chain from a lower leel to a higher level

Question 14

what is microplastics

Answer 14

plastic that are less than 5mm long

Question 15

what are the sources of microplastics

Answer 15

healthcare and beauty products, big pieces of plastic broken down

Question 16

what is bioplastics

Answer 16

made form biomass resources

Question 17

give the formula of pressure

Answer 17

pressure = force/area

Question 18

give the formula of moment

Answer 18

force x distance (nm)

Question 19

where did the early atmosphere get used up

Answer 19

phtosynthesis
trapped in fossil fuel
trapped in sedimentary rocks

Question 20

the smaller the surface area of contact, the ________the pressure

Answer 20

larger

Question 21

what is the law of reflection

Answer 21

angle of reflection = angle of incidence

Question 22

a red car appears red under ______ light and ________ light

Answer 22

red and white

Question 23

name the atomic model suggested by jj thompson

Answer 23

plum pudding model

Question 24

what is a galaxy

Answer 24

made of stellar dust, gas, stars and solar systems held together by gravity

Question 25

where is the asteroid belt located

Answer 25

mars and jupiter

Question 26

to form haemoglobin, what are the nutrients needed

Answer 26

protein and iron

Question 27

iron is important for making ______

Answer 27

haemoglobin

Question 28

why do we need fiber in our diet

Answer 28

to prevent constipation

Question 29

what substance found in cigarette which can lead to addiction

Answer 29

nicotine

Question 30

what is a joint

Answer 30

a place where two bones meet

Question 31

what attach muscles to bones

Answer 31

tendons

Question 32

state the movement of ball and socket joint

Answer 32

circular

Question 33

state the movement of hinge joint

Answer 33

back and forth, one direction

Question 34

why do tendons not stretch

Answer 34

the bone cannot move

Question 35

what is antagonistic muscles

Answer 35

a pair of muscles which work oppositelu

Question 36

when you bend your arm, the biceps ___ while the tricep _______

Answer 36

contract, relax

Question 37

during endothermic reaction, thermal energy is _______

Answer 37

absorb

Question 38

explain why you get a fizzy feeling when you eat sherbet

Answer 38

carbon dioxide is produced

Question 39

what is found in chemical ice pack

Answer 39

ammonium nitrate and water

Question 40

function of chemical ice pack

Answer 40

reduce swelling

Question 41

what is found in self heating can

Answer 41

calcium oxide and water

Question 42

what is the formula for sherbet sweets

Answer 42

citric acit+sodium hydrgogencarbonate = sodium citrate+water+carbon dioxide

Question 43

what is galvanizing

Answer 43

covering iron with zinc

Question 44

why sodium and potassium must be stored under oil

Answer 44

to prevent it reacting with water vapour and oxygen in the air

Question 45

write a word equation for the reaction between potassium and water

Answer 45

potassium hydroxide+hydrogen

Question 46

write a word equation for the reaction between magnesium and water

Answer 46

magnesium oxide+hydrogen

Question 47

the stronger the magnet, the ________ number of magnetic field lines

Answer 47

more

Question 48

the stronger the magnet, the ______ the magnetic field lines

Answer 48

closer

Question 49

the magnetic field lines start from ____ pole to ______ pole

Answer 49

north, south

Question 50

3 ways to strngthen the electromagnet

Answer 50

add soft iron coil increase number of coil increase the currrent

Question 51

suggest an application of electromagnet

Answer 51

doorbell

Question 52

suggest one difference between permanent magnet and electromagnet

Answer 52

permanent magnet cannot switch on and off

Question 53

why the reaction between magnesium and steam is more vigorous then the reaction between magnesium and water?

Answer 53

more energy move faster particls

Question 54

difference between endothermic reaction and process

Answer 54

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)