Physical And Chemical Change Flashcards
What is a physical change
It is a change that is temporary and the substance returns to its original state once it has been cooled.
What are some physical changes that a substance can go through
The temp may increase The substance may expand The substance may change colour The conductivity of metals decreases The substance may change phase
Why would the temp change
Because heating a substance increases the average kinetic energy, causing the particular of a substance
Why may a substance expand
Heating a substance increases the speed at which the particles move in the substance, thus the particles occupy more volume so the substance may expand
Why may a substance change colour
It may change colour because if a metal is heated it begins to glow red. Electrons are energised and jump into higher energy levels, when they return to the original energy level they emit energy which we see in the form of light
Why does the conductivity of metals decrease
When a metal is heated, the particles start moving more which makes it difficult for the electrons to move through to the positive terminal.
What is chemical change
When a chemical change takes place, a new substance is formed.
