science
what is it?
systematic study of the natural and physical world through observation, experiment and analysis
not confined to the laboratory and shows itself in all aspects of our lives
science main areas
physics
chemistrytext
biology
the meaning or explanation why things happens in the universe
theory that help us to predict what might happen in the future
helps to create machines and inventions which improve our surroundings and the quality of life. the use of scientific knowledge for practical purposes called technology
science laboratory
rules
do not enter a laboratory or carry out any experiments without supervision from your teacher
Students should never ever work in science lab in the absence of their teachers.
Students must follow all the written and verbal instructions when conducting the science experiment. In case they do not follow anything, they must clarify it first.
It is very important to be alert and be cautious when in the science laboratory. Eating, drinking, playing pranks, using mobile phones, or listening to music should be strictly prohibited.
Before using any chemicals, read the label carefully. When mixing chemicals or conducting the experiment, keep the test tube containing the chemical away from your face, mouth, and body.
Unused chemicals should never be put back in the original bottle. They must be disposed off as per the guidelines given by the lab assistant or science teacher.
Students must be made to wear safety goggles, lab coat, and shoes in the science laboratory. Loose clothes, sandals, and open hairs should be a strict NO in school science labs.
Examine glassware before using. Do not use chipped or cracked test tubes or beakers.
Hot apparatus take time to cool down. Allow time to cool them down and use tongs or heat protective gloves to pick them up.
If any accident takes place, do not panic. Inform your teacher immediately and lab assistants for help.
science lab symbol
properties of matter
numerical value
unit
S.I. base unit ( systeme international )
length = metre (m)
mass = kilogram (kg
time = second (s)
temperature =kelvin (k)
mutiples of the base unit
explotion substance
toxic substance
flammable substance
irritable substance
corrosive
radioactiven substance
matterial measurement
five main groups of materials
metals
glass
ceramic
plastic
fibres
mass
the mass of an object is amount of matter it contains
matter is anything that takes up place and has mass
measured by equipment called balance
volume
amount of three dimensional sspace the object occupies
unit = cm3
the equipment of measurement
a metre rule
used to measure short lengths
measuring tape
used to measuring outdoor distance
internal calipers
used to measure internal dimension of hollow object
external calipers
used to measure dimensions of round or cylindrical objects
vernier calipers
used to measure external diameter of round objects
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objects
irregular
measuring using displacement methods
regural
cube
cuboid
cylinder
sphere
cone
the density of a substance is its mass per unit volume
density = mass : volume
state of matter
solid
liquid
gas
ray model of light
light
form of energy that enables us to see
it can travel through a vacuum (empty space)
it has a speed of about 300 million metres per second
object that give out light energy are said to be luminous object
light travels in straight lines along paths which are called light rays
shadow
area of darkness on the surface
formed when opaque object [one that does not allow light to pass through]
eclipse
total or partial blocking of sunlight when one celestial body [earth or moon] passes in between the sun and other celestial body
solar eclipse
when the moon moves into the position directly between the sun and the earth
lunar eclipse
when the earth moves into a position directly between the sun and the the moon
reflection is the bouncing off of the light from an object
light that reflected either undergoes regular or irregular(diffuse) reflection
regular reflection
occurs on a perfectly flat surface such as a plane mirror
irregular/difuse reflection
occurs on uneven surfaces such as a white wall or a sheet of paper
plane mirror
white wall
upright
literally inverted [turned from left to right]
virtual [ can't be captured on a screen]
always the same size as the object
always the same distance behind the mirror as the object is in front
periscope
two angled mirrors can be used to see over walls or around corners
convex mirrors curve outwards
the image is smaller and distorted
concave mirrors curve inward
virtual but magnefied and upright image
refraction
the bending of light
caused by a change in the speed of light
effects
objects in the water appear closer
object will appear at the surface
electrical systems
electricity
a form of energythat result from the flow of charged particles
easy to changed
current consists of moving charges
measuring using instrument called ammeter
electrical comopnents
series
parallel
measuring using ammeter
measuring using volt meter
resistance
the ratio of the potensial difference across the component to the current passing through the component
formula
ressistence = voltage across component [ v ] : current through component [ I ]
aplication of forces
electtrolytes
liquid conductors of electricity
2 main electrolysis
chemical decomposition
electroplating
force
pushing or pulling action
invisible
we only can see the the effect
SI unit of force is newton (N)
forcemeter
used to measure the force
with an extension spring balance
with a compresssion spring balance
formula
speed = distance: time
force attraction between earth and an object
gravitational force
effect
the objectt fall towards the surface of earth
the pulling action on an object due to the gravitational force acting on the object is called weight
pressure
force acting per unit area
formula
pressure = force(N) : area(m2)
depends on force & area
energy and work done
when a force moves an object through a distance
formula
work = force x distance
energy
energy is ability to do work
when work is done, energy is always tranfered
immortal
types of energy
potensial
kinetic
chemical
gravitational
elastic
sound energy
made by vibrating objects
cannot travel through vacuum (empty space)
speed
330 metres per second
reflect sound waves
much slower than the light
speed of sound=distance travelled (m):time taken (s)
echo
frequenzy is measured byy heartz (Hz)
heat energy
make material expansion
SI unit = kelvin
the use of expansion
bimetalic thermometer
bimetallic strip
riveting
hot air ballon
measure using temperature
heat transfer
conduction
confection
radiation
transfer without medium
transfer by the movement of that material itself
transfer using solid
chemical composition of matter
all living and non living matter consist of basic units called elements
element is a substance which cannot be broken down into two or more simpler substances by chemical means
some element uncombined on earth
example; gold and silver
most occur uncombined with other elemeents
oxygen
the most abundant element is
nitrogen
all known elements are arranged in a chart called periodic table
every element is represented by a chemical symbol
each vertical column in the peoridic table is called a group
each horizontal row in the periodic table is called a period
elements in the periodic table can be classified into metals and non metals according to their different physical properties
metals
non metals
good conductor of heat
good electrical conductors
can be pulled into wires (dutile)
can be beaten into a shape (malleable)
give a ringing sound (sonorous)
shiny to look (lustrous)
high densities
poor conductor of heat
poor electrical conductors
non ductile
brittle and snap easily
not sonorous
dull appearance
low densities
compound is a substance made when twoo or more different elements chemically combine together
mixture
mixture
two or more substances that are not chemically combined together
mixture
two or more substance that are not chemically combined
homogenous
heterogenous
solution
sollute
weak
suspenssion
separation techniques
mixture
separate using physical properties of constituents of mixture
magnet attraction
evaporation
filtration
distillation
paper chromatography
reverse osmosis
compound
using chemical reaction
the particulate nature of matter
electrolysis
distillation
matter
all around us
made up of individual particles with spaces between the paricles
not continous
the particulate theory of matter moving in a random manner
have kinetic energy
made up of individual particles such as molecules or atoms which are arranged differently in solids,liquids, &gasses
a change in state
melting
freezing
boiling
condensing
atom & molecules
atom
the smallest particle in the universe
cannot be seen even using a powerful microscope
100 atom known
represent as a circle
neural particle
maude up of 3 sub atomic particles
proton
neutron
electron
can be split to nuclear energy that can be used to generated electricity for homes and factories
molecules
atom that combine together
chemical changes
chemical reaction
combustion
thermal decomposion
oxidation
neutralization
represent by word equation
new substance that made because chemical reaction called product
the effect of chemical change
heating matter
photosyntesis
diversity of living things
species
the set of genus
closely related species are called a genus ( plural:genera )
similar groups of animals or plants
biodiversity
biodiverse areas
a measure of the total number of the different living plants and animals in an area
less likely that a particular animal or plant will die out
most biologist agree that biodiverse areas called biodiversity hotspots are the most important areas for conservation
much better at recovering from nattural disaster
diversity of living things
species
the set of genus
closely related species are called a genus ( plural:genera )
similar groups of animals or plants
biodiversity
biodiverse areas
less likely that a particular animal or plant will die out
most biologist agree that biodiverse areas called biodiversity hotspots are the most important areas for conservation
much better at recovering from nattural disaster
a measure of the total number of the different living plants and animals in an area
cell
cell are the basic building unit of all living organism
simple organism such as amoeba are made up of only one cell
the majority