is the range of measurements within which the true value can be expected to be found. On apparatus, it is half the value of one resolution marking.

provides quantitative information about an object or system.

is an average calculated by adding up the values of a set of measurements and dividing by the number of measurements in the set.

is the smallest change a piece of apparatus can measure - shown by its markings.

a piece of equipment that is designed for a particular use.

Uncertainties in measurements: chemistry

Combined science

Three types of chemical reaction

Conservation of mass

Balancing equations

Mass in a chemical reaction

In the Making salts unit, pupils will learn about the production of pure salts, concentration and strength of acids, and what makes acids acidic and how bases can neutralise them.

In the Understanding Chemical Reactions unit, pupils learned about how atoms rearrange during chemical reactions and the conservation of mass.

This unit covers writing chemical formulae, balancing equations, and using the conservation of mass. It includes calculating moles, empirical formulae, relative formula masses, and theoretical yields. Emphasis is on stoichiometry, concentration, gas volumes, and using standard form.

Calculations involving masses

The range within which the true value can be found.

What does the uncertainty of a measurement indicate?

Quantitative information about an object or system.

An average calculated from a set of values.

The smallest change a piece of apparatus can measure.

A piece of equipment designed for a particular use.

Match the term to its correct definition.

How does a higher resolution affect the uncertainty of a measurement?

{{}} is the range of measurements within which the true value can be expected to be found. It reflects the limitations of our measuring devices.

The resolution of a measuring device is 0.02 g. What is the uncertainty of an individual measurement?

Equipment choice has no impact on the outcome.

Different equipment can yield different levels of precision.

Better equipment always guarantees the correct value.

Equipment choice affects the colour of the data.

Why is it important to consider the choice of equipment when conducting measurements?

Which piece(s) of laboratory equipment are typically used for measuring volume?

Which mathematical operation(s) would you use to calculate the average of three measurements?

In an experiment, what type of variable is the one that the scientist changes?

The amount of sunlight each plant receives.

In an experiment measuring the effect of sunlight on plant growth, what is the dependent variable?

Significant {{}} refer to the digits in a measurement that are known with certainty plus the first digit that is uncertain.

An error that has an equal probability of being too high or too low.

The closeness of two or more measurements to each other.

The degree to which a measurement reflects the true value.

A variable that is kept constant throughout an experiment.

Match the following terms with their correct definitions:

Exit Quiz

What does the uncertainty of a measurement indicate?