Bell Work
We observed two chemical change experiments.
One of the experiments produced hydrogen gas.
Tell me two reasons we believe we have produced hydrogen gas.
OBJECTIVE
To understand the characteristics of matter
To understand the properties of matter.
To distinguish between compounds, solutions, and mixtures
What is Matter and Volume?
Matter - Anything that has mass and volume.
Volume – the space an object occupies
These are tools that are used to measure matter.
Mass - balances or scales
Volume - flasks, graduated cylinders
Length - meter stick
What are the 3 Basic States of Matter?
Solid – definite shape and volume
Liquid – definite volume; takes the shape of its container
Gas – indefinite volume and shape; depends on the container
What about vapor?
What is Vapor?
Gaseous state of a substance that is liquid or solid at room temperature.
Example: Steam
Water is a liquid at Room Temperature
Quick Quiz: True or False
A vapor and a gas are the same thing.
False
A liquid takes on the shape of its container.
True
A solid has a definite shape but a changeable volume.
False
What are physical properties?
Physical properties: can be determined without changing the nature of the substance.
Examples: color, hardness, melting point, boiling point, and Density.
Describes a substance
What are chemical properties?
Chemical properties: can only be identified by trying to cause a chemical change.
* example:
Many substances share the chemical property of reactivity with oxygen.
Evidence of a Chemical Change
Evolution of a Gas The Formation of a Precipitate The Release or Absorption of
Energy Color change
Group Collaboration: Physical or Chemical Property
Shiny Red Good Conductor Reacts with Air Changes color when in contact with HCl Produces CO2
Temperature Forms Rust
Physical Or Chemical Property
Physical
Shiny Red Good Conductor Temperature
Chemical
Reacts with air Produces CO2
Changes Color Forms Rust
PHYSICAL CHANGES
WHAT ARE PHYSICAL CHANGES?
Changes in which the identity of a substance doesn’t change.
Examples of Physical Changes
Water changes to iceSugar dissolves in teaCrushing a rockCutting paperWater fogs a mirror
Closure:
Write 3 examples of physical changes
Write 2 examples of chemical changes
Write 1 thing about matter