Unit 1: The Scientific Endeavour

Involves the 5 senses (sight, touch, smell, taste, hearing) Usually descriptive or what you can observe with your 5 senses (e.g. heavy, long, fast)

Involves senses and measurements taken using instruments Has units, measurements or a numerical value e.g. 2 ants, 500g, 50s

• the act of attentive monitoring or perceiving, mediated through our five senses • the measurement, collection or recording of data, mediated through instruments, especially during an experiment

• a logical conclusion that can possibly be derived based on the observations made.

Variable Measured (VM) A dependent variable is what you measure in an experiment and what is affected during the experiment. The dependent variable is affected during the experiment. The dependent variable responds to the independent variable.

Variable Changed (VC) An independent variable is the variable you have control over, what you can choose and manipulate. It is usually what you think will affect the dependent variable.

The factors within an experiment that are kept the same for all groups or trials in an attempt to reduce the influence of irrelevant variables.

Controlled Variables (?) The group in an experiment that receives the exact treatment as the experimental groups except it does not receive any change of the independent variable. It is the group to which the experimental groups are compared.

A tentative (i.e. not final and definite) and testable proposed explanation for an observed phenomenon. It is based on observation and prior knowledge of the system. • It refers to only one dependent variable and one independent variable. • It is written as a definite statement, and not a question. • It is testable by experimentation.

The act of attentive monitoring or perceiving, mediated through our five senses and the measurement, collection or recording of data, mediated through instruments, especially during an experiment.

A conclusion, based on facts, which a person perceives to be true.

The replication of experimental and control groups is used to decrease the influence of variations associated with the independent variable and researcher measurement error.

Readings are closest to real value but may not be close to one another.

Readings are closer to one another even if it is far from real value.

Parallax Error • Occurs when you did not read the marking of an instrument at eye level or did not read perpendicularly above the marking • error in reading an instrument as a result of not viewing the measurement scale from the correct position. • Unpredictable (human error) • Can be corrected by reading the marking of an instrument at eye level or reading perpendicularly above the marking • Factors that contribute to unpredictable errors include unpredictable environmental conditions and human reaction time in operating a stopwatch.

• Occurs when a measuring instrument gives a reading not zero (when nothing is placed on it) when the true reading at that time is zero. • Consistent error = consistently inaccurate • Can be corrected by pressing the ‘tare’ button before placing something on the electronic balance or subtract (the amt that error causing) from final reading of mass • Occurs in measuring instruments e.g. weighing scale

• flame is not as hot as non-luminous flame • yellowish-orange, blue • sooty • flickering and unsteady • more visible • obtain when air-hole is closed • flame burns less efficiently (incomplete combustion)

• flame is very hot • pale blue, blue • not sooty • steady • less visible • obtained when air-hole is open • flame burns more efficiently (complete combustion)

It is due to the presence of carbon.

Opening the air-hole will produce a non-luminous flame which is hotter and burns more efficiently than a luminous flame.

Luminous Flame

yellowish-orange, blue

Luminous Flame Soot is produced when there is incomplete combustion / insufficient oxygen

Luminous Flame