Random
For a pyramid of numbers, the width of the bar shows the__________ of organisms present in each trophic level at a particular time.
Numbers
Name the unit for pressure
Pascal or Newton/m2
What does the arrow in a food web indicate?
Flow of energy
Name one element from the halogen group
Fluorine/Chlorine/Bromine/Iodine/Astatine/Tennessine
Describe the test to determine the presence of hydrogen gas
Lighted splint - squeaky pop sound
State the substances that will produce calcium chloride and hydrogen gas
Calcium + hydrochloric acid
Three parts of levers
Fulcrum, load, effort
Give one example of an adaptation rhinos have to their environment.
- Thick skin (protect from sharp grass and thorns)
- Large ears (pick up sound from many directions
- Horns (defence and attack)
Name the subatomic particles that can be found in the nucleus of an atom.
Neutron and Proton
One feature of wind-pollinated flower
Feathery stigma, Small and light pollens
Lack colourful petals
How to calculate density?
Density = Mass/Volume
A solid rock has a mass of 28g and a volume of 7cm3, find its density.
4 g/cm3
Explain the importance of decomposers.
They return minerals to the soil for the plants.
State four conditions that affect the rate of reaction.
Surface area, presence of catalysts, concentration and temperature
Formula to calculate moments
Moment = Force x Distance frm pivot
Specific part of the plant that contains pollen
Anther
How wading bird’s wide flat feet reduce the pressure on the ground?
A larger surface area exerts less pressure, therefore preventing the bird from falling into the soil.
Give an example of characteristics influenced by both genes and environmental factors.
Health eg: Height
Name the atomic model that JJ Thomson proposed.
Plum pudding model
The higher the altitude, the ............... the atmospheric pressure
Lower
Find the element with 11 protons.
Sodium
Explain why a moment is greater when farther from the pivot.
The larger the distance, the larger the value when multiplied by the mass.
Why are antibiotics that were used before for treating a disease no longer usable?
The bacteria become resistant towards the antibiotics.
Describe the trends in melting points for the Group 7 elements.
It increases as it goes down the group
The current atomic model was proposed by
Niels Bohr/Ernest Rutherford