end of year 8 test science Flashcards
properties of metals
good conductors of heat and electricity,
shiny,
solids with a high melting point,
flexible and malleable
properties of non-metals
poor conductors of electricity and heat
dull
most are low melting point solids or gases
brittle (break easily instead of bending)
state some uses of metals
e.g. copper is used in electrical wires as it is flexible and good conductor of electricity
what is a catalyst?
A catalyst is a substance that speeds up a reaction without being used up
Potassium + oxygen = ?
potassium + oxygen= potassium oxide
what is rusting
rusting is the corrosion of iron
what is the formula for rust
iron + water + oxygen = iron hydroxide
word equation for how water reacts with metals
metal + water = metal hydroxide + hydrogen
what is the test for hydrogen gas?
a burning splint should go of with a squeaky pop sound if hydrogen is available
what is the test for oxygen ?
get a glowing splint and place it in oxygen and it should relight
what is the test for carbon dioxide?
bubble carbon dioxide into limewater and if carbon dioxide is there is should turn MILKY
what is the reaction of an acid and a metal ?
metal + acid = salt + hydrogen
why are alloys better than metals/elements?
because they are stronger, melt over a range of melting points, prevent corrosion and etc.
why are alloys stronger than elements?
because alloys have different shaped atoms which disrupt the regular structure making it harder for the layers to slip over each other.
what is Dalton’s atomic theory
All matter is made up of tiny particles called atoms.
Atoms are indestructible, and cannot be created, or destroyed.
The atoms in an element are all identical.
During chemical reactions, atoms rearrange to make new substances.
what are some chemical changes?
some example of chemical changes are colour change, bubbles( formation of a gas), surroundings increasing or decreasing temperature and change in smell.
what is the law of reflection?
angle of incidence is equal to the angle of reflection if the surface is flat.
what is diffuse reflection?
the angle of incident is not the same as angle of reflection.
what are the Types of lenses?
Concave lens: The centre of the concave lens is thinner than the edges.
Convex lens: The centre of the convex lens is thicker than the edges.
What is refraction?
refraction is when light bends when going through a translucent or transparent material.
what is focal length?
focal length is the distance between the centre of the lens and the focal point.
name two specialised cells in the eye?
cone cells- allow you to see colour
rod cells- react to light
name three primary colours?
blue,red,yellow
what are the parts of a sound wave?
https://www.google.com/search?q=parts+of+a+sound+wave&rlz=1C1CHBF_en-GBGB972GB972&sxsrf=ALiCzsYcVdrEwqlbH6g-KVtDY-gcm2OmYw:1655653029121&source=lnms&tbm=isch&sa=X&ved=2ahUKEwj646-V7Ln4AhWxmFwKHVRzB0UQ_AUoAXoECAEQAw&biw=1440&bih=757&dpr=1#imgrc=2ydSSvvBbjQdmM
