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Matter. Matter is anything that: a) has mass, and b) takes up space What are the 3 states of matter? What are the properties based on which you classify them?. EXAMPLES OF PHYSICAL PROPERTIES:. SIZE. COLOR. SHAPE. DENSITY. TEXTURE. SMELL.
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Matter • Matter is anything that: a) has mass, and b) takes up space • What are the 3 states of matter? • What are the properties based on which you classify them?
EXAMPLES OF PHYSICAL PROPERTIES: SIZE COLOR SHAPE DENSITY TEXTURE SMELL
These physical changes may be through the following processes: MELTING FREEZING VAPORIZATION CONDENSATION SUBLIMATION
A change in which physical properties of a substance change, but the substance remains the same. The change is reversible. A. PHYSICAL CHANGES
Examples of CHEMICAL PROPERTIES 1. FLAMMABILITY -the ability to burn 2. REACTIVITY- The ability to combine easily with other atoms to form new and different substances.
When a chemical change occurs, the bonds between atoms break, and the atoms rearrange to form new and different substances.
The properties that describe how a substance changes into other new substances are called CHEMICAL PROPERTIES
a.Chemical changes are often called “CHEMICAL REACTIONS”
b. Example H2O + O2 H2O2 During this chemical change, the bonds between atoms break and the atoms rearrange to form new and different substances. (The equation above is not balanced)
Properties are… • Words that describe matter (adjectives) • Physical Properties- a property that can be observed and measured without changing the material’s composition. • Examples- color, hardness, m.p., b.p. • Chemical Properties- a property that can only be observed by changing the composition of the material. • Examples- ability to burn, decompose, ferment, react with, etc.
LAW OF CONSERVATION OF MATTER: MATTER IS NEVER CREATED OR DESTROYED.(After the chemical change, you have the same number of atoms that you had before the chemical change.)
PhysicalChange • Substance may seem different, but the way the atoms link up is the same.
It’s a physical change if • It changes shape or size • It dissolves.
It’s a physical change if... • It changes phase (freezes, boils, evaporates, condenses)
Chemical Change • Changes the way the molecules link up • Makes new substances
It’s a chemical change if…. • It burns • Temperature changes without external heating/cooling
It’s a chemical change if... • It bubbles (makes a gas)
It’s a chemical change if... • It changes color • It forms a precipitate
Physical vs. Chemical Change • Physical change will change the visible appearance, without changing the composition of the material. • Boil, melt, cut, bend, split, crack • Is boiled water still water? • Can be reversible, or irreversible • Chemical change - a change where a new form of matter is formed. • Rust, burn, decompose, ferment
What kind of change is it if someone... • Tears up paper? • Mixes salt and water?
What kind of change is it if someone... • Burns paper? • Evaporates salt water?
What kind of change is it if someone... • Mixes vinegar and baking soda?
Task-3 • List out 15 changes that happen around you on a normal day (from the time you wake up till you go back to sleep), classify them as physical / chemical changes , justify each classification.