CHEMISTRY Chemistry is the study of matter .
-It's composition structure, and properties
-The process it goes through and the energy changes that occur
Matter is anything that has mass and volume.
-Mass= a measure of the amount of matter
-Volume=a measure of how much space something takes up
Everything is made of matter
Atoms are the building blocks of matter.
Atom= the smallest unit of an element that maintains the identity of the element.
Exmaple= atmospheric nitrogen, N2 conatins 2 atoms of the element nitrogen.
Element= a pure substance that cannot be broken down into simple and more stable substances(elements).
Example= anything in the periodic table.
Compound= a pure substance that can be broken into simple and more stable subtances(elements)
Made from chemmically combining atoms of two or more elements.
Example=H2O
Matter
Substance Mixture
Element compound homogeneous. heterogeneous
Subtances= pure
-Fixed composition throughout
-Same properties througNaCI, C6H12O6
Element = form of matter
-on the periodic table
-cannot be broken down into anything simplier or more stable
-exist naturally as 1 atom(monoatomic) or two atoms
Examples= C, O2, something
Compounds= chemically combined atoms of 2 or more different elements.
Fixed proportions, written as a formula.
-Can be chemically broken into simplier and more stable subtances(elements)
-Have different properties as a compound than the parts that make it up
Example= NaCI, CO2, C6H12O6
Mixtures= combination
Variable composition throughout
Each component retains its unique properties.
-Mixtures can be separated into substances
-Examples= salt water, lemonde, blood, air
Homogeneous mixture= even destribution" same"
-Appears blended
-can be physically broken down into different components
-Solution: one subtance(solute) is dissolve into another(solvent)
-Aqueous solution= when the solute is dissolved into water
-Alloy: A sollution of metals
-Examples: Lemonade, stainless steel.
Heterogenous mixture: Uneven destribution" different"
-Can be physically broken down into different components and often easily
-components can often be seen or seperated out over time.
-Examples: Salad dressing, paint, blood.
Properties
Extensive: depends on the amount of matter that it presents
-Ex. Mass, volume, amount of energy, ect.
-Aluminum can have a mass of 10g or a mass of 200g based on how much you have.
Intensive= do not depend on the amount of matter that is present
-ex. Density, melting point, boiling point, specific heat, ect.
-Aluminum always has a density of 2.7 g/cm to the power of 3, regarless of if you have a few pieces versus giant sheets.
Physical= can be observe without changing the identity of the subtance
-ex. Density, boiling point, state, color
-State of matter
-solid: definite volume and defined shape
-liquid: definite volume and undefined volume
-Gas: Indefinite volume and indefinite volume.
Chemical: Can be only be observed by changing the compositions/identity of the subtance.
-ex. Reactivity, ability to decompose, instability.
Physical changes: Chages in the substance that doesn't chnage its density
-ex. Boiling, melting, dissolving, vaporizing, cutting.
Chemical changes: Chance of a substance into another substance; when a chemical reaction occurs.
-ex. Burning, oxidation, rotting, corroding, fermenting
-chemical changes do not have a change in amount of mass/matter
-law of conservation of matter: matter is never created or destroyed, it only changes form
-chemical changes always cause a change in composition.
Evidence of chemical reacton:
-Release of light
-sudden tempeture change
-sudden color change
-odor change
-gas given off
-sudden apperance of a solid
-this solid that forms is known as a precipitate.
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