Graphing
Is the Y-axis horizontal or vertical?
Vertical
Repetition is...
Reliability
What type of change forms a new substance?
Chemical
Do exothermic reactions release or absorb heat?
Release
Which direction is heat transferred between objects of different temperatures?
Hot to cold
What are the two main forms of energy?
Kinetic and potential
Does the independent variable go on the X-axis or Y-axis?
X-axis
Validity is...
Measuring the aim, controlling the experiment
Is ice melting physical or chemical?
Physical
Is an instant COLD pack an exothermic or endothermic reaction?
Endothermic
Name three methods heat can be transferred
Convection, conduction, radiation
Is thermal energy kinetic or potential energy?
Kinetic
Is it reasonable to increase the numbers on a graph as follows: 1, 3, 7, 15, 21, 23
No, because they are not in even intervals
A student repeats an experiment multiple times, but does it differently each time. Is this reliable?
No, because it needs to be repeated the same
Name three pieces of evidence a chemical change has occurred
Colour change, bubbling, precipitate formation, temperature change, emission of light or odour
Name an example of an endothermic reaction
Photosynthesis, instant cold pack, baking soda and vinegar, cooking an egg
What conducts heat the best?
What is something that affects how much gravitational potential energy an object has?
Its mass or its height above the ground
A students wants to test how the time of day affects water levels of a lake. Is this going to be a LINE or COLUMN graph?
Line graph (continuous)
A student wants to find out how fast a whale can swim. In their test, they measure a shark's speed to be 50km/hr. Is this valid?
No, they didn't measure the speed of a whale
How is melting sugar a physical change, but caramelisation a chemical change?
Melting sugar is reversible, caramelisation is not
Is there more or less chemical energy in the REACTANTS of an exothermic reaction?
More energy, because exothermic reactions RELEASE energy
How does heat travel through a metal rod?
Energetic particles bump into each other and move down the rod
Electricity travels from the wall through your charger and into your phone. Is this energy transfer or transformation?
Transfer
A student is measuring how the temperature of water affects how quickly salt is dissolved. They take the average from each temperature and use it to graph. Is this a COLUMN or LINE graph?
Column, because the average of each temperature (categories) was used
A student wants to test how fertiliser affects plant growth. They measure the plant from different heights each time they record it. Is this accurate?
Why is mixing blue and red paint a physical change rather than a chemical one, even though the colour changes?
The chemical structure of the paint doesn't change
During photosynthesis, plants use sunlight to make glucose. Does this reaction form chemical bonds, or break them?
Forms chemical bonds, because it's absorbing sunlight energy to MAKE glucose
How do convection currents work?
Hot water rises and cold water sinks. Heat from below heats the bottom water, which rises, then cools at the top, falling back down to the bottom in a cycle
A book is thrown into the air then hits the ground. Name an energy transformations that has occurred
Elastic to kinetic, gravitational to kinetic