Quiz #1 Flashcards
What is matter?
Any substance that takes up space and has volume (Solid, liquid or gas)
What are the two different types of matter?
Pure substances and mixtures
What is a mixture?
- two or more compounds or elements NOT chemically combined
- no reaction between substances
- mixtures can be uniform (homogeneous) and are known as solutions
- mixtures can also me non-uniform (heterogeneous)
- mixtures can be separated into their components by chemical or physical means
- the properties of a mixture are similar to the properties of its components
What are the two different types of mixtures?
Uniform solution (homogeneous) and mechanical mixtures (heterogeneous)
What is a uniform solution?
A mixture that looks like a pure substance
What are examples of uniform solutions?
- koolaid
- salt water (sea water)
- air
- tap water
What is a mechanical mixture?
A mixture that when looked at, you can see the different particles that make up the mixture and are usually able to separate them physically
What are examples of mechanical mixtures?
- cereal
- omelettes
- chocolate chip cookies
What is a pure substance?
Only one type of substance
What are the two different types of pure substances?
Compounds and elements
What is a molecule?
A particle made of two or more atoms bonded, but they could be two or more atoms of different elements
What is a compound?
- A molecule made of two or more atoms of at least two different elements chemically bound together
- always uniform
- compounds can’t be separated by physical means. To separate a compound requires a chemical reaction
- the properties of a compound are usually different than the properties of the elements it contains
What are examples of compounds?
- distilled water
- water (H2O)
- sulfuric acid (H2SO4)
- alchohol
- ammonia (NH3)
- dry ice (CO2)
What are elements?
- a pure substance containing only one kind of atom
- an element is always uniform all the way through (homogeneous)
- an element cant be separated into simpler materials (except during nuclear reactions)
- over 100 existing elements are listed and classified on the periodic table of elements
What are examples of elements?
- oxygen
- sulfur
- copper
- diamond
- uranium
- iron
- gold
What is a qualitative property?
Something that can describe an objects colour, or texture
What are examples of qualitative properties?
- rough texture
- grainy
- reddish-brown colour
- reflects light
- invisible
What is a quantitative property?
Something that describes and objects temperature, size, etc.
What are examples of quantitative properties?
- melts at 97 degrees
- covers 5.2 hectares
- liquid at room temperature
- large
What is an atom?
The basic unit of a chemical element
What is a physical change?
- a change of matter from one form to another without change in chemical properties
- usually reversible (ex.melt- freeze the same substance, dissolving)
- never changes identity of a substance
What are examples of physical change?
- cutting your hair
- a piece of metal is bent in half
- water freezes to form ice
- glass breaking
What is a chemical change?
- a change that occurs when a substance changes composition by forming one or more new substances
- a change that changes/ alters the chemical identity of a substance as a result of A NEW SUBSTANCE that have different properties
What are examples of chemical changes?
- baking soda reacts with vinegar and forms a gas
- copper turns green when exposed to the environment
- a tree burns to form ashes
- a piece of apple rots on the ground
