Marking a scale on a measuring instrument. This involves establishing the relationship between indications of a measuring
instrument and standard or reference quantity values, which must be applied.
For example, placing a thermometer in melting ice to see whether it reads zero, in
order to check if it has been calibrated correctly.
A unit of energy (heat)
The cycle by which carbon is exchanged between the Biosphere, geosphere, hydrosphere and atmosphere of the Earth.
Major activities include photosynthesis, respiration and decay between atmospheric and terrestrial systems.
Carbon dioxide (CO2)
The greenhouse gas whose concentration is being most affected directly by human activities. The major source of emissions is fossil fuel combustion.
A measure of the effect that human activities have on the climate in terms of the total amount of Greenhouse gases produced
A tax on energy sources which emit Carbon dioxide into the atmosphere. It is an example of a pollution tax.
Categoric variables have values that are labels. Eg names of insects or types of material.
A change in one variable that results from or is caused by a change in another variable
The smallest structural and functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane
The acceleration of an object moving in a circle at a constant speed. Centripetal acceleration always acts towards the centre of the circle
When fission neutrons cause further fission, so more fission neutrons are released. This goes on to produce further fission.
Consortium of Local Education Authorities for the Provision of Science Services
Climate change refers to the variation in the Earth's global climate or in regional climates over time. It describes changes in the atmosphere over time scales ranging from decades to millions of years. These changes may come from processes within the Earth, or be caused by human activities
Farms set up for the sole purpose of producing crops and farm animals for sale, with the sole intention of making a profit.
A confounding variable is one that may, in addition to the variable independent variable, affect the outcome of the investigation. Confounding variables must be kept constant or the investigation will
not be a fair test. Confounding variables are sometimes referred to as control variables.
Conservation of momentum
In a closed system, the momentum before a collision/event is equal to the total momentum after the collision/event.
A force that acts at the point of contact between two objects
Continuous variables can have values (called a quantity) that can be given a magnitude either by counting (as in the case of the number of cars) or by measurement (eg electrical current, speed etc).
A control experiment is one that is set up to eliminate certain possibilities. In a well designed investigation, the independent variable is changed and all confounding variables are kept constant. The possibilityexists, however, that something else other than the independent variable might have produced the results that were obtained. A control experiment is one that is designed to eliminate this possibility
A control group is one that is treated in exactly the same way as the experimental group except for the factor that is being investigated. This allows scientists to make a comparison. It ensures that the data
that are collected are valid because any differences between the results for the experimental group and those for the control group will be due to a single independent variable.
A control variable is one which may, in addition to the independent variable, affect the outcome of the investigation and therefore has to be kept constant or at least monitored.
A lens that makes light rays near and parallel to the principal axis converge to a point, known as the principal focus
A correlation shows that there is a relationship between two
variables, however, it might not be a causal one
Crotalus atrox, the western diamondback rattlesnake, is a venomous rattlesnake species found in the United States and Mexico. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the second-greatest number in the U.S., after C. adamanteus.