ks3 science Flashcards
how many planets are in our solar system?
8
what shapes are the paths of asteroids and comets?
ovals
What holds our solar system together?
gravity from the sun
what does terresrtial mean?
earth like
which planets are terrestrial planets?
mercury, venus, earth, mars
which planet is the hottest in our solar system?
venus
why is venus the hottest planet in our solar system?
it has a large concentration of greenhouse gases in its atmosphere
which planets are gas giants?
jupiter, saturn, uranus, neptune
what seperates the terrestrial planets from the gas giants?
an astroid belt
give two reasons why pluto is a dwarf planet
it is to small to qualify as a normal planet and it has not cleared its orbit.
what are comets made out of?
ice
what is the largest planet in our solar system?
jupiter
what is a lightyear?
the distance in which it takes light a year to travel across
what is the equation for distance?
speed x time
what are the two types of waves?
transverse and longitudinal
is light a transverse wave or a longitudinal wave?
transverse
is sound waves longitudinal waves or transverse waves?
longitudinal
what is the difference between weight and mass?
mass is a measure of of the amount of matter an object is made out of whereas weight is the force that acts on mass due to gravity
what is the equation for weight?
mass x gravity
why will somebody’s weight be different on earth then on mars?
there is more/different gravity on earth then mars
will a falling feather move faster on earth or on the moon and why?
it will move faster on the moon because it is a vaccume therefore air resistance will not act on the feather
What unit is energy measured in?
joules
what is the equation for density?
mass / volume
what is the equation for volume in a regular shape?
length x width x height
which state of matter has the least density?
gas
which of the states of matter can be compressed?
gases (and very few liquids- do not have to know this for exam)
what affects the amount of current flowing through the circuit?
resistance
what shape is the symbol for a resistor?
rectangle
what can voltage also be referred to as?
potential difference
what is the equation for resistance?
potential difference (voltage) / current
what elements are magnetic?
iron, nickel, cobalt
what material is often used to show a magnetic field?
iron fillings
which way does a magnetic field flow?
north and south
What are the three states of matter?
gases, solids and liquids
what is melting?
a solid becoming a liquid
what is freezing?
a liquid becoming a solid
what is condensation?
a gas becoming a liquid
what is evaporation?
a liquid becoming a gas
what is solid CO2 called?
dry ice
What is the most important thing to remember about energy?
it cannot be created or destroyed
what does an electromagnet use to create a magnetic field?
electrical current
how can you strengthen an electromagnet?
increase the current
increase the number of turns in the coil
add an iron core
what is the difference between an electromagnet and a normal magnet?
you can turn an electromagnet off
do opposite poles attract or repel?
attract
does the same pole attract or repel?
repel
what is the equation for speed?
distance / time
what is the equation for relative speed?
fastest speed- slowest speed
what is an element?
a pure substance that cannot be broken down into any other substances
how many elements are there in the periodic table?
118
what is a compound?
A compound is a substance that is made from more than one element that are chemically bonded together.
what is a mixture?
when multiple compounds or elements are together but are not chemically bonded
what is the chemical symbol for sulfuric acid?
H2SO4
what is the ph for acids?
1-6
what is the ph for alkalies?
8-14
what is the ph for a nuetral substance?
7
what colour is the universal indicator in a neutral solution?
green
what colour is the universal indicator in a alkaline solution?
blue - purple
what colour is the universal indicator in acidic solution?
red - orange
what do you need for a neutralisation reaction to take place and what is the result?
you need an acid and an alkali and it creates a neutral solution
how would you describe a reactive element?
it takes part in many chemical reactions
what is a displacement reaction?
a reaction where a more reactive element replaces a less reactive element in a chemical reaction
what are the horizontal rows of the periodic table called?
periods
what are the vertical columns of the periodic table called?
groups
what happens to the melting points as you go down group one of the periodic table?
decrease
what are the properties of a metal?
high melting and boiling points
good conductors of heat and electricity
they are shiny
they are malleable
what are the properties of non-metals?
poor conductors of heat and electricity
dull in their appearance
weak and brittle
what happens in an oxidation rection?
a substance gains oxygen atoms
what gas is needed for fuel to burn?
oxygen
what is thermal decomposition?
a chemical reaction that happens when a compound breaks down when heated.
What is the conservation of mass?
the law that during chemical reactions no atoms are created or destroyed
what is combustion?
combustion is the same as burning. in a combustion reaction, fuel is burned and reacts with oxygen to release energy
what charge has a proton got?
positive
what charge is a neutron?
neutral
what charge is an electron?
negative
what charge is an atom?
neutral
what are the seven life processes and what acronym is used to remember this?
acronym= MRS GREN
movement, respiration, sensitivity, growth, reproduction, excretion and nutrition
what is biodiversity?
the range of living organisms in a habitat
what process moves oxygen from the alveoli to the blood?
diffusion
what is diffusion?
particles moving from an area of high concentration to an area of low concentration
give two reasons how alveoli is adapted for gas exchange?
has a large surface area, is only one cell thick, they have moist surfaces
what is created when anaerobic respiration takes place?
lactic acid
what is the name of the type of respiration that requires oxygen?
aerobic respiration
Approximately how long is the menstrual cycle?
28 days
On what day of the menstrual cycle is an ovum released?
around day 14
what hormone do females have an increase of through puberty?
oestrogen
what hormones do males have an increase of through puberty?
testosterone
what hormone do females have an increase of through the second half of the menstrual cycle?
progesterone
what is found in plant cells but not animal cells?
cell wall, vacuole and chloroplasts
what is the role of the cell wall?
keeps the cell firm and rigid
what is the role of the cell membrane?
controls what goes in and out of the cell
what is the role of the cytoplasm?
where the chemical reactions take place
what is the role of the mitochondria?
where respiration takes place
what is the chemical found in chloroplasts and what is its role?
the chemical is chlorophyll and the role of the chloroplasts is to carry out photosynthesis
what is the role of the vacuole?
to store cell sap
what is the role of ribosomes?
where protein is produced
what is the role of the nucleus?
to store DNA
how many chromosomes does each cell contain?
46
what organ produces bile?
the liver
how many chambers does your heart have?
4
how is a red blood cell adapted?
large surface area, they do not respire aerobically, they have large amounts of heamoglobin and they have no nucleus
