Particles & Substances
What is the name given to a substance made from only one type of atom? (hint there are 118 flavours)
element
Name the change of state when a solid becomes a liquid.
Melting
What type of energy store does a moving object have?
Kinetic energy store
What type of energy is transferred when a hot object warms a cold object?
Thermal energy
What is the name for the variable that a scientist deliberately changes?
Independent variable
How many atoms are there in one molecule of CO₂?
Name the change of state when a gas becomes a liquid.
Condensation
What energy store does a raised object have because of its height?
Gravitational potential energy store
What energy transformation occurs when a battery powers a torch?
chemical → electrical → light
What is the name for the variable that is measured during an investigation?
Dependent variable
Which two elements are present in carbon dioxide, CO₂?
Carbon and oxygen
What happens to the kinetic energy of particles when a substance is heated?
It increases
What type of energy store does a stretched elastic band have?
Elastic potential energy store
A cyclist brakes and comes to a stop. Describe the main energy transfer that occurs.
Kinetic energy is transferred mainly into thermal energy in the brakes, tyres and surroundings.
What is a control variable?
A variable that is kept the same to make the investigation a fair test.
A sample contains 5 molecules of H₂O. How many hydrogen atoms are present?
5 x 2 = 10
Why does a liquid take the shape of its container but keep approximately the same volume?
Its particles are close together but can move/slide past one another.
Name four types of energy stored in or associated with a hot potato being thrown at someone.
Kinetic, Gravitational, Chemical, Thermal
What happens to energy when it is dissipated?
It is transferred/spread into the surroundings, usually as thermal energy and sometimes sound.
A student investigates whether the length of a pendulum affects its period. What is the dependent variable?
The period of oscillation
Table sugar is a compound with the formula C₁₂H₂₂O₁₁. How many different elements does it contain?
Three. Carbon, hydrogen and oxygen
What is the change of state called when a solid changes directly into a gas?
Sublimation
A rock falls from a cliff and lands on a teacher. What energy transformation is taking place as the rock falls?
Gravitational potential energy → kinetic energy.
A torch is 80% efficient. 1 kJ of energy is transferred from the battery. How much energy is wasted as heat?
200 J
A student investigates how different amounts of fertiliser affect the growth of plants. They use the same type of plant and measure the height of each plant after four weeks. Name three controlled variables that should be kept the same to make this a fair test.
Amount of water
Amount of sunlight
Type of plant
Type and amount of soil
Size of pot
Temperature
Age/starting size of the plants