WorksheetsScience Revision
Total questions: 25
Worksheet time: 14mins
How many atoms are there in one molecule of calcium carbonate, CaCO3?
3
4
5
6
What does the diagram represent?
atoms of element
molecules of element
molecules of compound
mixture of elements
What does the diagram represent?
atoms of element
molecules of element
molecules of compound
mixture of compounds
What does the diagram represent?
molecules of element
molecules of compound
mixture of elements
mixture of element and compound
What is a molecule?
smallest particle of an element
two or more atoms chemically combined
Which current does the arrows on the diagram show?
red: conventional current, blue: electron
blue: conventional current, red: electron
What does this circuit symbol represent?
fixed resistor
variable resistor / rheostat
fuse
What does this circuit symbol represent?
fixed resistor
variable resistor / rheostat
fuse
Which of the following are precautions to prevent electrocution?
I. Electrical appliances or gadgets must not be used in wet places.
II. Call a certified electrician to repair damaged electrical appliances or cables.
III. Do not insert any item, such as a screwdriver, into an electrical socket.
I and II only
I and III only
II and III only
All of the above
The earth wire provides a path of _________________ for a large current to flow directly from the live wire to the ground or earth if there is a fault in an electrical appliance.
low voltage
high voltage
low resistance
high resistance
What is S?
earth wire
live wire
neutral wire
fuse
Name wire P.
earth wire
live wire
neutral wire
Name wire Q.
earth wire
live wire
neutral wire
Which one of the following expands the most for the same rise in temperature?
solid
liquid
gas
When alcohol is cooled, its density
increases
decreases
remains constant
becomes zero
A dented ping pong ball returns to its normal shape when placed in hot water. This is because
water enters the ball.
air escapes from the ball.
the surface of the ball expands.
air inside the ball expands.
In the diagram below, what do you think will happen when the air in the flask is cooled?
Water enters the glass tube.
Bubbles of air are pushed out of the glass tube.
Heat from the water is transmitted to the air in the flask.
Nothing happens.
When you stand in bare feet with one foot on a stone floor and the other on a carpet, the stone floor feels colder than the carpet. The most likely explanation is that
air is unable to circulate through the carpet.
more heat energy flows from the carpet to your foot than from the stone floor to your foot.
more heat energy flows from your foot to the stone floor than to the carpet.
Water in a beaker is heated at X. Which diagram best shows the convection currents?
A
B
C
D
The diagram shows a crystal being heated in a beaker of water. The crystal releases a dye which shows how the water circulates around the beaker. What is happening to cause the water above the crystal to rise?
The water contracts and its density decreases.
The water contracts and its density increases.
The water expands and its density decreases.
The water expands and its density increases.
Buildings in deserts are painted white to
increase heat absorption by radiation.
reduce heat absorption by radiation.
increase heat absorption by conduction.
reduce heat absorption by conduction.
Sound is produced by
vibrations
heat
light
waves
Loudness in sound is measured in
joules
watts
decibels
dioptres
Humans are unable to hear sounds beyond the frequency of
20 Hz
20 kHz
200 Hz
2000 Hz
Sound cannot travel through
solid
liquid
gas
vacuum
