Integrated Science Mr. Danckers Chapter 2.1

Key Ideas Why are color, volume and density classified as physical properties? Why are flammability and reactivity classified as chemical properties?

 Matter has many different properties. These properties make things useful for different purposes.  Physical Properties: can be observed without changing the substance of the object ◦ Color ◦ Shape ◦ Texture

 Physical properties can help identify things  Hair and height can identify friends  Pure water is clear and colorless

Physical properties can be observed or measured.  State – the physical form of a substance - solid, liquid or gas  Melting Point: the temperature at which a solid becomes a liquid  Boiling Point: the temperature at which a liquid turns to a gas

Other physical properties are:  Strength  Hardness  Magnetism  Conductivity  Flexibility  Abrasion resistance  More…

Physical properties help determine uses Copper is used in power lines because it conducts electricity well Aluminum is used in foil because it is light weight yet durable and flexible. Why is Styrofoam used for holding hot drinks?

Density is a physical property of matter Density= mass/volume  water has a density of 1.00g/ml  objects with a density less than 1.00g/ml will float

Mass and Density Paper Lab  Do all initial work on a piece of loose-leaf paper.  Only when your group has reviewed and agreed on an answer may you transfer your answer to the lab form. (Neatness counts!)  Show all work and calculations, including units.  Written answers must be in complete sentences.

 Chemical Properties  Chemical properties describe how a substance changes into another substance ◦ May combine with other elements ◦ May break apart into new substances

 Flammability – the ability to burn ◦ Burning is a rapid reaction with oxygen that releases heat  Reactivity – the capacity to react with another substance ◦ Iron reacts with oxygen slowly to form iron(III) oxide. ◦ Chromium does not.

 The Big Difference…  Physical properties can be observed without altering the material’s substance  Chemical properties describe how changeable a substance is.