Fizzes And Bangs Flashcards
What is a physical change?
A change which the form of matter is altered but no one substance is not transformed into another and no chemical bonds between atoms and molecules are broken.
What is an example of a physical change?
Ice to water
Water - water vapour
What are signs of a physical change?
- change of size or shape
- change in state of matter
- reversible
- no new substance formed
What is a chemical change?
When particles that make them up undergo change. Usually occurs when the chemical bonds between particles in molecules are broken or a new chemical substance is formed.
What is an example of a chemical change?
Raw egg to a hard boiled egg
What are the signs of a chemical change?
- new substance formed
- solid disappears or disappears
- temp change (spontaneously)
- colour change
- bubbles or fizzing appears
- A flame or light is produced
Why is baking a cake an example of a chemical change?
When an acid is added to bi carb soda , a new substance carbon-dioxide is produced . When cream of tar tar dissolves in liquids it forms tactic acid.
What is the word equation for iron oxide?
Iron + water + oxygen ——> rust (iron oxide)
Why does rusting occur?
When iron comes in contact with moisture and oxygen which damages the structural integrity and aesthetics of iron.
What are some ways rusting can be limited?
- coating it with paint, plastic, or oil
- Regular cleaning , drying and oiling
- Glavanising (coating metal with zinc , which is more reactive metal than iron, which means it is more likely to take part in chemical reactions)
