Chemical and Physical Reactions Flashcards
Is dissolving sugar a physical or a chemical change?
Physical
Signs of a chemical change?
Gas released, colour change, odour produced, temp changes, light, sound produced, precipate may be formed, bubbling, reactants dissapearing
What are reactants?
Substances that we begin with
What are products?
Substances that are formed (by reactants)
How are chemical and physical changes different?
Physical changes can usually be reversed, but chemical changes usually cannot. No new substances are created during a physical change but during a chemical change, the substance at the beginning is always changed at the end.
What is a chemical change simply?
A process that involves changes to the chemical inside of a substance which makes new molecules, compounds and atoms
What is a physical change simply?
A process involving changes in state, usually changes in size or form or matter.
When do chemical reactions occur?
When one or more substances rearrange their particles into different things to create a new substance
What happens during a physical change? (the properties)
-Returns to original form
- No new substance is created
- change in colour
- melting
- change of size, state, density
- no change in atom bonds
-melting point, boiling point,conductivity
What is the meaning of opaque and is it a chemical or a physical property?
-physical property
-cant be seen through
What is the meaning of transparent and is it a chemical or a physical property?
-physical property
-clearly see through something
What is translucent?
Light can pass through but objects on the other side cannot be seen
What is malleable?
Can be hammered
What is ductile?
You can bend or shape a substance like metal
