Matter
What is mass and volume?
mass is measured in metric ( SI) units called grams or kilograms. Volume is measured in units called either cubic cm for solids or millimeters for liquids. i cm3 is a volume equal to 1 ml.
What is a chemical changes?
A change that occurs that causes the identity of a substance to change; something new is formed. New substances with new properties are formed.
What are physical changes?
A change that occurs. Without changing the identity of the substance. No new substances are formed.
What are Molecules= Combining Atoms?
A molecule is a group of atoms that are joined together to act as a single unit; this molecule is the smallest piece of a compound. A chemical bond is the force that holds the atoms of the molecules together.
What is the law conversion of mass?
Antonie Lavoisier, 1770's. Chemicals finally had accurate balances. Carried out chemical reactions in a closed space. showed that the mass of the material before the change equals the mass of the material after the change. LAW CONVERSION OF MASS: No matter was created nor destroyed.
What are chemical properties?
Are determined by a substance's ability to react with other substances.
What are your 5 physical properties?
Are determined by the use of the five senses. They are a description of an object.
Examples of mass
Canned goods at the grocery store now show both the English measure for weight and the metric mass.
Examples of physical changes
Changes of state. Change in size shape or color. Pencil shavings Torn paper Crushed ice Sugar dissolved in water Painting a wall
Examples of physical properties
Color Smell Taste Hardness States of matter Boiling, freezing, or melting point
Examples of physical properties
Density Mass Volume Malleability ( The ability to be molded) Solubility ( The ability to be dissolved)
What is Density?
Density is a measure of how much mass of a substance is contained in a certain volume. Density has to be calculated by comparing mass and volume.
How is density a characteristic property/
Density is the same for all samples of a substance. EX: Pure gold always has a density that measures 19.3 g/cm3. Since density remains the same, it can be used to identify types of matter.
What is matter and thermal energy?
ENERGY: The ability to do work or cause change. Every chemical or physical change in matter includes a change in energy. EXAMPLE: As water changes from a solid to a liquid to a gas, it's thermal energy increases.
What Are Properties of Matter?
EXAMPLES: hardness texture, temperature, shape, flammability, size and color. " States" of matter includes solid, liquid and gas; state depends on temperature.
What is a Pure Substance?
Made of only one kind of matter with one set of properties; EX: Elements or compounds
What is an Element?
Elements cannot be broken down into simpler substances. There are 100 elements known at present. Many familiar elements are metals while some are nonmetals.
What are the two different types of mixtures?
HETEROGENEOUS: You can see the different parts ( Ex- salad, soil, pizza) HOMOGENEOUS: A mixture so well-mixed that you cannot see the different parts. Solution ( Koo laid). Colloid- evenly mixed; will not settle out, particles larger than in a solution 9 Honey, milk, jello).
What is comparing densities?
If a great deal of matter is packed into a small space, this give a very high density value. If the matter is more loosely packed the density value is low.
What is property?
It is a description of an object.
What is a Compound?
It is matter consisting of 2 or more elements that are chemically combined to form one pure substance. EX: Table salt
Using Characteristic properties to test Unknowns
MELTING POINT: The temperature at which a solid melts is characteristic for each kind of substance. BOILING POINT: The temperature at which a liquid boils is characteristic for each kind of substance. EX: Pure water always boils at 100 degrees C. Liquids that may look alike can be identified by testing their boiling points.
Describing Matter
Matter is anything that has mass and takes up space. Everything in the universe is made up of matter.
What is Classifying Matter?
Mixture- when 2 or more kinds of matter are placed together, but are chemically combined into one substance; this means each kind of matter each part has its own properties; often they can easily be separated.
What is a second separation technique?
Most elements cannot be found in their pure state Ore is any rock that contains useful metals combined with other substances Ores are mined fro the Earth and then a complex series of steps is used to isolate the useful metal The last step in this process is called ELECTROLYSIS which means electric cutting
What is A Characteristic property?
Never changes. Can be used to identify a particular type of matter. Some properties can change ( Size or shape of a piece of wood), But characteristic properties remain the same. Every sample of particular kind of matter will have the same characteristic properties. Therefore... an unknown sample of matter can be identified by looking at its characteristic properties.
How do we separate element from the Earth for our use?
Only a few elements can be found in a pure from in the Earth. Many are found as part of mixture. In 1848 John Sutter found several gold nuggets in the river near his mill; this discovery sparked the Californian gold rush. prospectors used the high density of gold to separate dust and nuggets from the stream bed by panning.
What are the two types of changes in matter?
PHYSICAL CHANGE: The form or appearance of a substance, but do not change its identity. CHEMICAL CHANGES: Cause a substance to break apart or combine with substances to form something new.
Identifying Unknown Substances
Requires comparing at least 2 characteristic properties for a match. This is necessary since different substances may share one characteristic property.
What is temperature verses thermal energy?
TEMPERATURE: A measure of the average energy of motion of the individual particles of a substance. THERMAL ENERGY: Total energy of all of the particles. heat- thermal energy moving from a warmer object to a cooler object.
Examples of chemical properties
The ability to react with air. Rust Tarnish Corrode Rotor and food rotting The ability to react with water and acids The ability to catch fire ( Flammability)
What is an Alloy Metal?
Two or more pure metals that can be melted down, stirred together; allowed to cool and harden. EX: Copper+ Zinc= Bronze
Why is weight not mass?
Weight- a measure of the force of gravity pulling you downward against a scale; this quantity will change depending on the pull of gravity. Mass- Not the same as weight; it is measure of the amount of matter contained in an object.
Examples of chemical change
Wood burning Metal rusting Food digesting Gasoline burning Cake baking Food rotting
