PHYSICS
Describe the law of reflection?
Angle of incidence = angle of reflection
What factors are needed for seed to germinate?
water, oxygen and warmth - WOW
what is the difference between element, compound and mixture
element - made of only 1 type of atom
compound - made of 2 or more DIFFERENT types of atoms chemically bonded together
mixtures - made of elements and compounds that are NOT chemically bonded and CAN be separated easily.
List down 2 differences each between bird and wind-pollinated flowers
Bird- bright. nectar, scent,anther inside the fower
wind- dull, non sticky light pollen, anther outside
Why can seeds germinate in a dark cupboard?
light is not needed
Describe how sound waves travel.
Longitudinal waves , sound energy is transferred through vibrations of particles
What is the function of heart?
Pump blood to body cells from lungs (carry oxygen and glucose to the cells for respiration)
Magnesium has atomic number of 12 and mass number of 24.
*What is the symbol of magnesium
*How many protons, electrons and neutrons does it have?
*What is the electron arrangement of Magnesium
Mg
12 protons, 12 electrons and 12 neutrons
(2,8, 2)
What happens to water when we heat it?
Evaporation, energy, less dense, forces, move further apart, turn into gas
Describe the process of cellular respiration.
glucose + oxygen --> energy + water + oxygen
Why does green leaf appear green when white light is shown on it?
white light is made of ROYGBIV
all colours absorbed except green which reflects back to the eye to appear green.
Name the 2 tubes that carry water and food to and from the leaf in a plant.
xylem - carries water from the roots to the leaves and pholem carries food away from the leaf to the rest of the plant..
Name the 3 states of matter and describe the arrangement of the particles in all of them.
SLG
particles - closer they are the stronger the forces of attraction between them with little spaces to move/vibrate
Describe with examples, physical and chemical changes
physical change - no new substance is made
chemical change - new substance made with observations that include a change in colour, gas produced, bubbles, smell, light/spark given off
how does light behave in concave and convex mirrors
reflect
concave - converge
convex - diverge
Sam is fishing. Describe how waves travel from air to water.
refraction, bends towards normal
Discuss how the dandelion seeds are dispersed and explain the importance of seed dispersal
wind, reduce competition for resources
Why does oil float on water?
Oil - Less dense-particles further apart, less MASS in the SAME volume
Water - more dense- particles closer together, more MASS in the SAME volume
Explain the Law of Energy Conservation using an example
Cannot be created, not destroyed but transforms or transfers
how are reproduction similar in plants and animals
gametes fuse.
sperm/male gametes travel to the female
zygotes are formed.
occurs in the female reproductive organ
Why can astronauts in space not hear each other but can see each other.
hear- sound - no particles- no vibrations, no energy transferred
Light- no particles
Discuss why pollination is important in plant reproduction
pollination is transfer of male gametes... leading to fusion of male and female gametes to produce zygote
Describe how will you get clean water from muddy water?
filteration/ evaporation/ condensation /distillation
why can a magnifying glass be used to burn paper
converges all light rays to a focal point where the paper is set on fire
Discuss the process of pollination and fertilization FULLY.
pollen -male gamete, stigma, pollen tube, ale gamete, fertilastion- fusion male and femal in ovary