SCIENCE

syllabus point

Qualitive

uses the 5 senses to observe ( touch, smell, taste, hear, sight)- descriptive

Quanatitve

uses numbers and measurements- numerical- recorded through graphs both line and column.

observation

 Includes information that's been acquired through any of the senses.

independent

change (cause)

dependent

measure (effect)

Archimedes Principle

• He found out that the amount of water displaced = volume of a subject

• Submerged the crown in water to measure the volume & used it to determine if its density was equal to gold.

• Density = mass 

                  Volume

Alexander Flemings

• He left his petri dish containing cultural bacteria poorly sealed & went on holidays

• Once he came back he observed that mould (penecillin) had grown

• The area around the mould was free of bacteria

• He isolated the mould & tested with different bacteria & found the cause effect.

• It was Australian scientist  Howard Florey who succeeded in separating and purifying the penicillin antibiotic.

Galileo Observations:

• While viewing Jupiter through his homemade telescope, he saw what he thought were 3 fixed starts in a line through the planet

•  After a month of observations he found out that it was 4 objects and that they were orbiting jupiter

• This led to the observation that contested the traditionally cosmology idea that there was one centre of motion in the solar system.

• He soon learnt that the stars were actually the moon.

Firestick Farming

• Adapted by the Aboriginal and Torres strait island peoples.

• Firestick farming is the same as modern day back burning.

• It was used to reduce the risk of bushfires, increase the amount/ diversity of food, heat from fire, increased germination of seeds, ash used as fertilizer, fresh vegetation attracted animals, also flushed out animals, used to make paths.

Bush Medicines:

• Used by Indigenous and torres strait islander peoples included:

• Tea Tree Oil: Crushes leads and applied the paste to wounds as antiseptic, it was also used as brewing for throat ointments

• Eucalyptus Oil: Infused for body pains, fevers & chills, can also be used as an antiseptic directly on the skin.

Emu Bush: leaves were used to wash sores and cuts, occasionally being gargled, also used as antiseptic.

Random Errors

• Reduces the reliability

• Will shift each from its try value by a random amount or direction

• They can be eliminated or reduced through repetition and averaging

Systematic Errors

• Reduces the accuracy

• Shift measurements from their true value by the same amount & same direction all the time

• Usually aries from the equipment, to eliminate them use calibrated equipment to eliminate any zero or parallax errors.

PH scale

Inference

Is the conclusion you arrive at based on evidence

Wonky Holes

• One way the underground water ( fresh water) flows into the ocean

• They are high nutrients & therefore home to rich areas of fish & supplies them with food & fresh water

• Submarine freshwater springs found along the great barrier reef

• Attract large numbers of fish & are throughout to act as nursery

Collision theory

• Chemical reactions can only take place when the reacting particles collide with each others

• The collisions must have sufficient energy

• Role of chemical reaction is determined by the frequency of successful collisions

• Particles in solution can only react with particles on the surface of the solid

• The rate of a reaction increases when we increase the surface area of a solid.

Surface area to volume ratio

• Smaller sized blocks of solid reactant have a greater surface area to volume ration than larger blocks

• Therefore they have more particles on the surface so there are more collisions per second

• This increases the rate of reaction

Why are secondary resources important in primary investigations?

• Scientific investigations require support

• Allows scientists to build on knowledge

• Can direct future investigations

• Prevents research that has already been completed from being repeated

Cave formations & chemical reactions:

• Limestone caves form from erosion due to carbon dioxide in water

• Caves form in limestone (calcium carbonate) & occasionally in dolomite (calcium magnesium carbonate), when water containing dissolved carbon dioxide seeps into rock crevices & joints

Secondary sources data can be used after a primary investigation to:

1. Validate & check if your original explantation is correct

2.  To see if our explanation is relevant in the investigation

3. To gain a deeper understanding of what scientific principles are at work

4. To open up new areas of interest, new question, future investigations

5. Apply & see relevance to other areas of life  & science

Making inferences

• All scientific investigations require evidence to support their findings

• Scientists can challenge the reasoning underpinning the inferences drawn from observations in previous studies and go on to test them

• This has the potential to establish an alternative of the evidence and overturn flawed conclusions

Develop inquiry questions

By other scientists & find gaps in the research where questions have not been fully answered to

Construct suitable hypotheses:

• Developed by making a proposition about how the independent variable and the dependent variable relate to one another (cause & effect).

• By reviewing the research a scientist can determine which variable and their relations to other variables have been tested in the past, how these variables may relate to a potential inquiry question and which variable may not have been tested.

Reasons to consult research:

1.  To learn from the research methods of other scientists to improve validity, & reliability

2. To avoid unnecessary investigations by seeing what investigations have been conducted in the past

3. To make inferences from the research by learning from the work of other scientists

4. To develop inquiry questions by determining which questions have been answered & which haven't

5. To construct hypotheses to test variables that may have been identified in the research

Fractals in nature:

•  made by a simple repeating process that can produce shapes of infinite complexity eg/ pyramids

• useful in modelling structures & identifying patterns in some phenomena that appear irregular

Fibonacci sequences (irregular):

• Is a sequence of numbers that goes 1,1,2,3,5,8,13,21…

• Each number is the sum of the two numbers before it

• Some plants exhibit the pattern like branches of trees, succulents and spider webs

The aurora australis (irregular):

• Light emitted when the upper atmosphere is hit by energetic charged particles, especially electrons from the solar wind, which travel along the earth's magnetic field lines.

• When these electrons collide with oxygen and nitrogen, the gases emit light, producing mainly greens, red and violet colours

type 1 error

when a hypothesis is incorrectly accepted

type 2 error

when a hypothesis is incorrectly not accepted

Paradolia

• The tendency to interpret a vague stimulus as something known to the observer eg/ seeing faces in objects or patterns

• Cognitive processes are activated by the face life object which alerts the observer to both the emotional state & identity of the object before the conscious mind processes the information

Optical Illusion:

• We have evolved to recognise patterns, often our brains cannot help but we see things that aren't there, even if we’re aware of them

• They are a result of our brain taking ‘shortcuts’ in order to interpret information quickly

Regression analysis

 statistical process of establishing the relationship between variables

Data outlier

data point distant from other observation & measurements that may indicate an error

correlation

refers to how closely related two sets of data are (variables)

Inverse correlation

 opposite ion directing, means there is an inverse relationship between two variables

Regression analysis (r)

is a statistical analysis of the relationship between two variables

Correlation coefficient

 the strength of the correlation, is described using an r value between -1 to 1