Chapter 11 Lesson 2 –Physical Properties

Melting Point Conductivity Mass Boiling Point Volume Density Physical Properties – each element and compound has a unique set of properties. Physical property – a characteristics of matter that you can observe without changing the identity of the matter.   Physical Properties include: Melting Point Conductivity Mass Boiling Point Volume Density Solubility States of Matter

Size-Dependent vs. Size Independent Properties 1. Size-dependent properties - depends on how much matter is in the sample. Mass and Volume are both size-dependent properties. Mass – the amount of matter in an object (mass is size-dependent because its value depends on the size of the sample). Example: Mass of a large dumbbell made of iron versus a small dumbbell made of iron. Remember that mass and weight are two different measurements. Mass = measures the amount of matter in an object Weight = measures the amount of gravitational force on an object. Example: On the moon the mass of the iron dumbbell would not change, the weight of the iron dumbbell on the moon would change because there is less gravity. Volume – the amount of space an object takes up. This is another physical property that depends on size.

Size-Independent Properties - do not depend on the amount of matter present. properties are the SAME for both large and small samples. Examples: States of Matter, Melting Point, Boiling Point, Density, Solubility, and Conductivity are all examples of size independent properties.

States of Matter States of matter (solid, liquid, gas) are physical properties of matter. The state of matter of a substance depends 2 things: 1. How close the particles in matter are to one another. 2. How quickly they are moving.

Melting Point/Boiling Point Melting Point – temperature at which a substance changes from a solid to liquid. Boiling Point – temperature at which a substance changes from a liquid to a gas. Example: boiling point of water = 100 °C Notice that the boiling point is 100 °C no matter what the size of sample.

Density – the amount of matter (mass) in a given volume of a substance. The density of pure gold is 19.3 g/cm3 no matter what size sample of gold you have.   Conductivity - Electrical conductivity is the ability of matter to conduct an electric current. Ex: Copper is often used in electrical wire because it has a high electrical conductivity. - Thermal conductivity – is the ability for a material to conduct thermal energy. Ex: Stainless Steel is used for pots and pans because it has a high thermal conductivity. -Metals tend to have a higher electrical and thermal conductivity.

Solubility- the ability of a substance to dissolve in another.

These are all physical properties of matter: