Ch 2.1 (Properties of Matter)

Transcription

1 Ch 2.1 (Properties of Matter)

2 matter Anything that has mass and takes up space is matter

3 Matter is described by two types of properties; 1. Physical Properties 2. Chemical Properties Properties of matter

4 Physical Properties describe matter Properties that are observed without changing the matter. Melting and boiling point are physical properties (the temperature at which a substance melts or boils) State of matter is also a physical property (solid, liquid, gas) Density ( a measure of how closely packed an object s atoms are)

5 Chemical property is the ability of matter to change into different matter. Chemical changes change the chemical nature and properties of substances to form new substances A match burns Two substances mix together turn a color different from either of them Toasting marshmallows Melt it physical change Burn it chemical change Chemical Properties

6 atom The smallest particle that can still be identified as the matter it came from is an atom

7 element Matter that is made of only one kind of atom is an element. Carbon, hydrogen, and oxygen are all elements. The picture is of the element zinc in hydrogen chloride. Zinc + HCL

8 Difference between COMPOUND & MIXTURE MIXTURE COMPOUND 1. A mixture can be separated into its particles by physical processes (filtration, evaporation, sublimation, distillation) 1. A compound cannot be separated into its constituents by physical processes. It can be separated by chemical means

9 2. Elements can combine in any ratio. 3. Elements do not react chemically. 4. Mixture shows the properties of its constituents 2. Elements combine in a fixed ratio. 3. Elements react chemically and make new substance. 4. A compound has new properties different from its constituents.

10 CH 2.2 (Changes in Matter)

11 Physical change-a change in state The substance is still the same substance Form changes but chemical makeup doesn t

12 Ice changes to water water changes to ice, frozen water is still water

13 Water changes to steam, a gas, when it is heated to its boiling point,water vapor condenses to form a liquid

14 Changing States of Matter-Water Water freezes at 0 degrees Celsius, 32 degrees Fahrenheit Water boils at 100 degrees Celsius, 212 degrees Fahrenheit emphys.html

15 Other Physical Changes Breaking Crushing Cutting Bending Melting Freezing Boiling Can happen naturally People can cause changes Water evaporating Rain falling and causing puffles People cause change Recycling paper Recycling metal

16 Chemical Properties and Changes Chemical changes change the chemical nature and properties of substances to form new substances A match burns Two substances mix together turn a color different from either of them Toasting marshmallows Melt it physical change Burn it chemical change

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18 Combustibility-a measure of how easily a substance will burn, or combine rapidly with oxygen Corrosion of metal when iron combines with oxygen in the air, rust forms Gas bubbles hydrogen peroxide on a cut A change in color--fireworks

19 Energy Physical and chemical changes are accompanied by energy changes. energy: the capacity to do work work: results from a force acting on a distance

20 Energy Conversions The Law of Conservation of Energy states that energy is neither created nor destroyed. Energy can change from one form to another or transferred from one object to another.

21 Temperature and Heat Temperature is the measure of the thermal energy of a substance. The hotter an object, the greater the motion of its particles, and the greater the thermal energy. Heat is the transfer or exchange of thermal energy caused by a temperature difference.

22 Thermal Energy Atoms and molecules of matter are in constant, random motion, which is the source of thermal energy. More motion = more thermal energy. Is there a way to easily measure this motion?