Physical Properties of Matter

Fundamentals of Matter

• Matter is defined as anything that takes up space. This encompasses everything from the air we breathe to large-scale structures like a skyscraper in a city.
• All matter possesses physical properties, which are characteristics that can be observed or measured to describe objects.

Identifying and Observing Physical Properties

• Some physical properties are observable through the use of human senses (sight, touch). These include:
  • Size
  • Shape
  • Color
  • Texture
  • Hardness
• Other properties require specialized tools or specific materials to determine. These include:
  • Temperature
  • Mass
  • Volume
  • Magnetism
  • Relative Density (the ability to sink or float in water)

Measuring Properties with Tools and Materials

• Volume:
  • Description: The amount of space a solid, liquid, or gas occupies.
  • Measurement: Can be measured using a graduated cylinder or by calculating the product of an object's dimensions.
  • Relationship: Larger amounts of substances correspond to larger volumes.
• Mass:
  • Definition: The amount of matter contained within an object.
  • Metric Unit: Measured in grams ($g$).
  • Mass vs. Size: Mass is not inherently tied to the external size of an object. For example, a small iron ball contains more matter and thus has more mass than a large cup made of foam.
• Temperature:
  • Definition: A measure of how hot or cold an object is, reflecting its thermal energy.
  • Measurement Tool: Thermometer.
  • Particle Dynamics: When heat is added, particles within an object gain speed and move further apart. Continuous heat addition can cause a state change (e.g., solid to liquid, liquid to gas).
  • State Change Example (Water):
  • Heating: Turns water into a gas.
  • Removing Heat: Turns water into a solid (ice).
• Magnetism:
  • Definition: A pushing or pulling force produced by a magnet.
  • Testing: Magnetic properties are determined by whether an object is pulled toward or pushed away from a magnet. Only specific materials exhibit magnetic attraction.

Relative Density: Sinking and Floating

• Relative Density: This is the scientific method used to determine if an object will sink or float compared to a reference material (usually water).
• Observation Rules:
  • Sink: An object falls to the bottom of the water. This indicates the material is more dense than water.
  • Float: An object stays on top of the water. This indicates the material is less dense than water.
• Application: Understanding relative density helps scientists compare the density of different materials by using water as a standard.

Practical Utility and Material Selection

• Selection for Purpose: Choosing materials for projects (such as construction) is based on the specific physical properties required for the environment.
• Environmental Adaptation:
  • Building in tornado-prone areas requires different material properties than building in earthquake-prone areas.
• Combining Materials: Materials can be mixed to improve their properties and better suit the needs of a project.
  • Example: Bricks: Strong bricks are made by combining clay and sand. The clay acts like a glue, binding the parts of the wall together to increase strength.

STEM Career Profile: Interior Designer

• Educational Requirement: A Bachelor’s degree.
• Compensation: The median salary is listed as $56,040.
• Primary Responsibilities:
  • Designing and furnishing rooms for residential homes and businesses.
  • Translating customer likes, dislikes, and ideas into aesthetic and functional spaces.
  • Staying compliant with business laws and the American Disabilities Act (ADA).
• Key Skills and Collaboration:
  • Strong communication and active listening.
  • Close attention to detail and creativity (innovative designs).
  • Knowledge of architectural basics.
  • Collaboration with contractors and plumbers to realize the client's vision.

Questions, Stop and Jots, and Discussion

• Think about It (Bowl of Soup):
  • Q: What physical property do you notice? When you eat food that has just finished being prepared, what do you have to be careful of?
  • A: One would notice the temperature (heat) and the steam (state change). One must be careful not to burn themselves due to high thermal energy.
• Stop and Jot 1: How do you use physical properties to make the soup safe to eat? (e.g., waiting for the temperature to decrease or testing the texture).
• Stop and Jot 2: What physical properties can be used to describe a skyscraper? (e.g., size, shape, color, hardness, mass).
• Stop and Jot 3: Give examples of matter that can be described using temperature (oven), mass (a weight), and magnetism (a refrigerator door).
• Stop and Jot 4: If a ship is made of metal that is more dense than water, then how does it float? (Note: This refers to the overall displacement and shape affecting buoyancy, though the material itself is dense).
• Stop and Jot 5: What materials are combined when baking a cake? (e.g., flour, eggs, milk, sugar; combined to change texture and state).
• Summarize It - Review Questions:
  1. What physical property should be observed if you were trying to decide what to wear? Answer: B. Temperature.
  2. What physical property is most likely being observed if the materials being used are a paperclip, scissors, and a nail? Answer: C. Magnetism.
  3. What physical property is being tested when determining the relative density of an object or substance? Answer: A. Ability to sink or float.
  4. Fill-in-the-blank: Mass tells how much matter is in an object.
  5. Fill-in-the-blank: Physical properties are characteristics that can be observed or measured.
  6. Relative Density Example: An example of relative density using everyday substances is oil floating on water because oil is less dense than water, or a lead sinker falling to the bottom of a lake because lead is more dense than water.

Virtual Field Trip: Glacier

• Observation of a glacier via QR code involves identifying properties such as state of matter (solid), temperature (cold), and color (white/blue).