Physical Changes
What does it mean to go through a physical change?
No new substances are made. It can go back to its original form.
What does it mean to go through a chemical change?
New substances are made. It can't go back to its original form.
What does the Law of Conservation of Mass mean?
It means matter cannot be created or destroyed.
It means that even when substances change form, their total mass (weight) remains unchanged.
What is on the Periodic Table of Elements?
Elements in the universe discovered and studied by scientists.
Wood, metal, and glass.
What is another term for physical changes?
Reversible change.
What is another term for chemical changes?
Irreversible change.
What is an example of Conversation of Mass in our daily life?
When we mix things or create things, their total mass is unchanged.
What element has the symbol O and is essential for breathing?
Oxygen
What are some examples of physical properties of materials?
Things you can observe without changing the material like colour, shape, melting point.
True or false: Baking bread is a physical change.
False
True or false: Baking bread is a chemical change.
True
When you break a chocolate bar into pieces, will the total mass change?
No, it will be the same unless you eat some!
What is the lightest and most abundant element in the universe?
Hydrogen
What are some examples of chemical properties of materials?
How a material reacts to form something new, like how burning wood turns into ash.
Give an example of physical change other than water.
Chopping wood, cutting paper
Give an example of chemical change other than cooking or baking.
Fire burning, rusting metal
When you burn wood, does the total mass change?
No, unless you fail to capture the gas (smoke).
Which element has the symbol Fe and is commonly found in our blood and helps carry oxygen?
Iron
Why wouldn't you use glass to build a cruise ship?
Because glass is too fragile and brittle to support the structure and weight of the ship.
Why is boiling water a physical change?
Because the water that you boil can evaporate into gas and that gas can cool down back into liquid, going back to its original form.
Why is digesting food in your stomach a chemical change?
Because your stomach acid is breaking down the food you ate so your body can absorb it easily. You also cannot undigest food.
When can the total mass change?
If the new substances created is spilled (solid or liquid) or floats away (gas), the mass can change.
What is the only metal that is liquid at room temperature and has the symbol Hg?
Mercury
Why would you use metal to make the head of a pickaxe?
Because metal is strong, durable and hard enough to break through tough materials like rock and dirt.