properties of matter. 2 essential questions: 1. what is matter? 2. what are some physical properties...

Properties of Matter

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Essential Questions:1. What is Matter?

2. What are some physical properties that can be used to describe matter?

3. What are some chemical properties that can be used to describe matter?

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What is Matter? (58-

61)

MATTER is anything that has mass (amount of material) and volume (amount of space taken up)

not matter=energy

a) Mass is the amount of matter in an objectVolume is : the amount of space that matter takes up

MATTER HAS DENSITY

• Density is: the amount of matter in a given space.

a) Density is calculated: Density = Mass Volume

b) Density is measured with a balance (for mass) and a graduated cylinder (for volume) using

the metric units g/ml or g/cm3

c) Water’s density is 1g/ml or 1 g/ cm3

• Every substance has its own density.

MATTER CAN BE DESCRIBED BY ITS PROPERTIES.

A. Property: a characteristic used to describe an object

B. There are 2 Types of Properties:

1. Physical property - a characteristic of a pure substance that can be observed without changing it into another substance

• examples: color, taste, odor, volume, mass, density, viscosity, solubility, melting point, boiling point, electrical or thermal conductivity

2 types of properties

2 types of properties

•Chemical properties:a characteristic of a pure substance that describes its ability to change into a different substance with new properties

• examples: rusting, flammable, reacts with vinegar

C. BOTH CHEMICAL AND PHYSICAL PROPERTIES ARE USED TO DESCRIBE AND IDENTIFY MATTER.

D. Matter can be identified by its properties that do not change even when the amount changes.

Some of these properties are: density, melting point, boiling point, and what it reacts with.

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Matter can be described by its properties

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Elements, Compounds, and Mixtures

Essential Questions:– What are characteristics and examples of

elements? – What are characteristics and examples of

compounds?– What are characteristics and examples of

mixtures?

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VI. Matter can be divided into 3 main categories (62-67)

A. ELEMENTS1. Elements are pure substances made up

of only one type of atom. They cannot be broken down into a simpler substance

2. There are about 115 known elements, • 92 natural• Rest are man-made

A. Elements cont.

3. Each element has its own atomic structure and a unique set of physical and chemical properties that identify it

4. The smallest particle of each element is the atom

B. Compounds

1. Compounds – a pure substance composed of two or more elements chemically combined, in a set ratio - smallest piece of a compound is called a molecule.

2. Most elements in nature are combined with other elements, most substances we use everyday are made of compounds.

B. Compounds cont.

3. When elements are chemically combined they form compounds with properties that are DIFFERENT from the original elements

4. Chemical formula - Compounds mix according to certain ratios, there is a set “recipe”– Ex: water is ALWAYS 2 hydrogen atoms

bonded to 1 oxygen atom

B. Compounds cont.

5. Compounds can be chemically broken down into the individual elements that form them

6. Each compound has its own set of physical and chemical properties that are different from the elements that form them– Water – clear liquid formed from two highly

explosive gasses– Table salt – white crystalline solid necessary for

cellular function formed from an explosive silvery metal and a poisonous green gas

C. Mixtures

1. A mixture is 2 or more substances PHYSICALLY combined

2. Each substance keeps its original physical properties

3. Parts of a mixture can be separated by PHYSICAL changes

4. Substances in the mixture can be any amount in the mixture (no set “recipe”)

C. Mixtures cont.

5. Two Kinds of Mixtures– a) Heterogeneous mixtures have particles

big enough to see, they are not evenly mixed and some particles are big enough to separate out.

– b) Homogeneous mixtures look the same throughout, they are evenly mixed and do not separate on their own.

b. Homogenous

1. Solutions: appear to be single substances but are made of at least two substances, one dissolved in the other

Ex: salt dissolved in water, hydrochloric acid dissolved in water, hot chocolate mix dissolved in milk

1) Solutions cont.

Concentrated – a lot of one substance dissolved in another

• Ex. Very salty salt water

Dilute – not very much of one substance dissolved in another

• Ex. Not very much salt in salt water

matter

elements compounds

mixtures

heterogeneous homogeneous

atoms

molecules

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Changes in Matter

Essential Questions:– What are some physical changes matter

can undergo?– What are some chemical changes matter

can undergo?– What is the law of conservation of matter?

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VII. Matter can change in two ways68-70

1) Physical change: a change in form or appearance, but no new substance is created; most physical changes are easy to undo.

• Change of State – physical change, ex: solid to a liquid; liquid to a gas, etc.

2. Change in form or shape – physical

change, ex: dissolving salt in water, bending metal, crushing, breaking, etc.

2) Chemical change: a change that occurs when one or more substances are changed into entirely different substances with new properties

Examples of changes

Physical Changes:Water freezing or ice melting,Cutting hair, Sanding wood,Bending a paperclip, Crushingan aluminum can

Chemical Change:Souring milk, bubbling or Fizzing when 2 things combine,Iron rusting, Bleach takingcolor out of something

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Energy

Essential Questions:– What are some forms of energy that are

related to changes in matter?– How do you describe when a change in

matter releases or absorbs energy?

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71-77

Law of Conservation of Matter - Matter is not created or destroyed in any chemical or physical change

Energy – ability to do work or cause change. Like matter, energy is never created or destroyed in chemical reactions, it can only be transformed (changed from one form to another)

Write in the blank space below energy:

Thermal energy – total energy of all of the particles in an object– Temperature – measure of the average energy

of random motion of particles of matter– Endothermic change – a change in which

energy is taken in. Ex: melting ice– Exothermic change – a change in which energy

is released. Ex: combustion – heat and light are produced.

Chemical energy – energy stored in chemical bonds between atoms, energy stored in the foods you eat, gasoline to fuel a car, etc.

Electromagnetic energy – energy that travels through space and waves. Ex: radio waves, microwave oven, etc.