SC2a - mixtures Flashcards
What are the characteristics of a pure substance’s composition?
It can’t be changed and is the same in all parts of a piece of a substance
What is an impure substance?
A substance made of more than one atom
What types of atoms are found in a pure piece of silver?
Silver atoms
Can compounds never be pure?
No they can also be pure as well as elements
What can’t a pure substance do?
Be separated into other substances using physical methods
What are the characteristics of a mixture?
You can use physical processes to separate the mixture into different substances and the don’t have a fixed composition
What happens when a solid melts in terms of particles?
They gain enough energy to overcome weak forces of attraction and move further away from each other to become a liquid
Give an example of a physical property of a substance
It’s melting point
Why are the physical properties of a pure substance the same?
As a pure substance has the same composition in every part of it
Is a substance that melts at 183 - 258 C and pure substance or a mixture?
Mixture as it has a range of melting points
