Chemical and Physical Properties and Changes

Matter Matter is everywhere. Matter is anything that takes up space and has mass. Matter is constantly experiencing both chemical and physical changes.

Physical Properties and Changes Physical Properties are used to observe or describe matter. How do you observe or describe someone? Height Hair Color Eye Color Weight Age Clothing Color Let’s describe Dwight Schrute

Physical Properties and Changes When we observe or describe something or someone we use “drivers license” descriptions. When we observe or describe MATTER we use some of the same descriptions.

List as many physical properties as you can…

Physical Properties and Changes Things you observe and can describe about matter: Color Size Smell Freezing Point Melting Point Mass Shape Volume Density

Physical Change Physical changes occur when matter changes its property but not its chemical nature. Physical property changes could include a change in: texture, shape, size, color, odor, volume, mass, weight, and density.

Physical Properties and Changes Do NOT change the structure of matter when they are observed or described. What does “structure” mean? How the atoms are stuck together! Each letter is a different atom, and the lines that connect the letters show the STRUCTURE of the substance. And here each color represents a different atom and this picture shows the STRUCTURE of the substance.

Physical Properties and Changes What is the “structure” of water? What is the “structure” of ice? What is the “structure” of steam?

Physical Properties and Changes We just observed one of the physical properties of H 2 O! PHASE CHANGE We observed how H 2 O is different in each phase, but the structure of H 2 O never changed!

Physical Change

The difference between Physical Property and Physical change. The physical property is something that we can measure with out changing the identity of the matter. That includes the materials ability to change shapes but not change what it is The physical change is the actual process of changing shapes. Remember that no new substance it formed!

Physical Properties and Changes When a physical property (like the phase of water) is altered we called it a PHYSICAL CHANGE In other words: A physical change involves a change in physical properties (shape, size, density, etc.) It takes a physical change to change water to steam, or ice to liquid. What are some other examples of physical changes?

Physical Properties and Changes Shape The shape of the wood changed. But is it still a piece of wood?

Physical Properties and Changes Shape

Physical Properties and Changes Color The tip of the nail changed color. But is it still a fingernail?

Physical Properties and Changes Melting Point The ice cream melted. But does it still taste like ice cream?

Physical Properties and Changes You can think of Physical Changes like changing the font of a word… Mr. Archibald The “structure” of the words is still the same, even though the physical appearance changed.

Chemical Change Chemical changes are changes matter undergoes when it becomes new or different matter. To identify a chemical change look for signs such as color change, bubbling and fizzing, light production, smoke, production of odor, and presence of heat.

Chemical Properties and Changes And you can think of Chemical Changes like rearranging the letters of the words… Mrs. Coates Most Acres Cream Toss Re: Mascots Me Toss Car Cares Most

Chemical Properties and Changes The letters are the same, but we’ve rearranged the structure and made new words! This is what happens in a chemical change! Chemical properties lead the way for chemical change

Chemical Properties and Changes What are some examples of Chemical Properties? Flammability Oxidation Toxicity Radioactivity Sensitivity to Light Reactivity with water

Chemical Properties and Changes Flammability: – The ability to catch fire!

Chemical Properties and Changes Oxidation – The ability to react with Oxygen

Chemical Properties and Changes Toxicity – The ability to be poisonous

Chemical Properties and Changes Sensitivity to Light – The ability to change when exposed to light

Chemical Properties and Changes Reactivity with water – Some elements react explosively with water! – Sodium, Potassium, Lithium, and Calcium

Chemical Change A chemical change occurs when fireworks are used. Fireworks are made of metals such as magnesium and copper. These change chemically as they light up the sky.

Examples of Chemical changes Soured milk Alka seltzer Statue of liberty being eroded by acid rain Space shuttle launch

Chemistry & Matter We can explore the MACROSCOPIC world — what we can see — We can explore the MACROSCOPIC world — what we can see — to understand the PARTICULATE worlds we cannot see. to understand the PARTICULATE worlds we cannot see.

Kinetic Nature of Matter Matter consists of atoms and molecules in ____.

The In-Betweens: Physical or chemical? Some properties (abilities) can be either physical or chemical Examples: – Ability to change color – Change in temperature

Both of these examples are making a gas. Which one is physical and which is chemical?

Both of these pictures show a color change due to heat: which is physical and which is chemical?

Lets Take the QUIZ… ownloads/ChangeLab.swf ownloads/ChangeLab.swf

1. Is it a chemical or physical change? Sugar dissolving in tea Chemical Change Physical Change

OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

Correct!

2. Is it a chemical or physical change? Logs burning Chemical Change Physical Change

OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

Correct!

3.Is it a chemical or physical change? Breaking water up by separating it into hydrogen and oxygen Chemical Change Physical Change

OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

Correct!

4.Is it a chemical or physical change? Cutting paper Chemical Change Physical Change

OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

Correct!

5.Is it a chemical or physical change? Crushing an aspirin Chemical Change Physical Change

OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

Correct!

6. Is it a chemical or physical change? Metal rusting Chemical Change Physical Change

OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

Correct!

7.Is it a chemical or physical change? Lighter fluid burning Chemical Change Physical Change

OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

Correct!

8.Is it a chemical or physical change? An egg rotting Chemical Change Physical Change

OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

Correct!

9. Is it a chemical or physical change? An egg breaking Chemical Change Physical Change

OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

Correct!

Writing Activity Write a paragraph about the difference between a chemical and physical change. Give examples of each.