Types of Substances (Mainly Gr.9 Review) Flashcards
What can a substance with constant composition (one type of particle) be classfied as?
It can be classified as either an element or as a compound.
What is the difference between a pure substance and a mixture?
A pure substance contains one type of particle while a mixture contains 2 or more types of particles.
What is a compound?
It is a substance that contains two or more elements. They are composed of more than one kind of atom.
What is a molecule?
It is composed of two or more atoms which may be the same or different.
What are some examples of a compound?
Table salt (sodium chloride, NaCl), sugar (sucrose, G2H22O11), and water (H2O).
What is an element?
A substance that cannot be seperated into two or more substances by ordinary chemical (or physical) means. They are composed of only one kind of atom.
What are some examples of an element?
Iron (Fe), copper (Cu) and oxygen (O2).
What is the difference between and element and a compound?
An element cannot be further broken down, while a compound contains 2 or more elements.
What is a mixture?
It is two or more substances combined. Each retaining its own specific properties. The components of a mixture can be seperated by physical means, i.e. without the making and breaking of chemical bonds.
What are some examples of a mixture?
Air, table salt thoroughly dissolved in water, milk, wood and concrete.
What is the difference between a compound and a mixture?
A compound has 2 or more elements. A mixture has 2 or more particles.
What is homogenous?
They can be classified as solutions: Mixtures which are uniform (not changing in form/character).
What is an example of a solution?
Air and table salt thoroughly dissolved in water (you cannot see the seperate elements because they are mixed well).
What is heterogenous?
Mixtures that are not uniform.
What are examples of a heterogenous mixture?
A salad, sand, stir-fry & mixed nuts.
