Which of the following are physical changes?
Dying hair
Boiling water
Chopping wood
Changing a solid into a gas is called...?
Solidification
Deposition
Sublimation
Condensation is when...
When a liquid is cooled enough to change from a liquid to a solid
When gas cools and becomes a liquid
When liquid is warmed and becomes a gas
Dissolving is when a solid is dissolved into liquid.
You can detect when a chemical change has occurred when...
Colour Change
Gas Formation (Bubbles or smell)
New substance being formed
Heat or Light is produced
Dissolves
Endothermic Change...
Absorbs energy from its surroundings. If it occurs in a test tube, the test tube will feel cold because the reaction absorbs heat from your skin.
Gives off energy in the form of heat, light & sound.
Gives you Frostbite
Everything is made from...
Cells
Molecules
moving light particles
Particles move faster because of heat and they need more room to cool down.
A solvent is...
The liquid in a solution
The solid dissolving in the solution
Density is the weight of an object.
Density is found by...
Dividing Mass by Volume
Dividing Volume by Mass
Multiplying Mass by Volume
Ethanol is denser than water.
Molecules are made up from...
Atoms
More molecules
Water is made up from 2 hydrogen atoms and 1 oxygen atom
All chemical reaction equations have 2 reactants and 1 or more products.
Magnesium Sulfate and Hydrogen Gas are products made from the reactants of...
Hydrogen and Magnesium
Sulfuric Acid and Oxygen
Magnesium and Sulfuric Acid
Spontaneous Reactions are reactions that proceed by themselves.
Rusting is the name given to...
Corrosion of iron
Corrosion of steel
A dog
Ways of preventing rusting are...
Coating
Alloying
Galvanising
Painting
You can write chemical reaction equations in...
Words
Symbols
Numbers