Chemistry Notes PDF

Notes-vocab 1 Qualitative observation one that can be made without a measurement. [Flowers are blue, water is made of hydrogen and Oxygen, iron magnetic. 2 Quantitative observation - one made that uses measurements. [6.5 grams of hydrogen, length or diameter of object]...

Notes-vocab 1 Qualitative observation one that can be made without a measurement. [Flowers are blue, water is made of hydrogen and Oxygen, iron magnetic. 2 Quantitative observation - one made that uses measurements. [6.5 grams of hydrogen, length or diameter of object] 3 Hypothesis - an explanation that can be tested. 4 Control group Standard to which the outcome of a test is compared to (model) 5 Independent variable-factor the experimenter changes (manipulated variable) 6 Dependent Variable - factor that changes in response to the independent variable. (data you are measuring), 7 Constants- all other factors that are left unchanged so they do not interfereMetric System Review Metric system ​ International System of units. used by scientist around the world Based of the number 10 Metric Unit Converting Between Common Metric Units of Measure The metric system is the system of measurement primarily used in science and in countries outside of the United States. The metric system includes units of length (meters), mass (grams), and capacity (liters). The base unit of length is the meter. The table below shows some of the most common metric units of length and how they are related to the meter.  millimeter (mm)=0.001 meter centimeter (cm)=0.01 meter meter (m)=1 meter kilometer (km)=1000 meters Notice that all metric units of length include “meter”. The prefix of each unit of measurement indicates how that unit relates to the meter. ​ “milli” means one thousandth. There are 1000 millimeters in 1 meter. ​ “centi” means one hundredth. There are 100 centimeters in 1 meter. ​ “kilo” means one thousand. There are 1000 meters in 1 kilometer. The same prefixes are used throughout the metric system. The base unit of mass is the gram. The base unit of capacity is the liter. The tables below show some of the most common metric units of mass and capacity and how they are related to the gram and the liter. milligram (mg)=0.001 gram centigram (cg)=0.01 gram gram (g)=1 gram kilogram (kg)=1000 grams milliliter (mL)=0.001 liter centiliter (cL)=0.01 liter liter (L)=1 liter kiloliter (kL)=1000 liters Temperature degrees, Kelvin Celsius Mass-measure of the amount of matter in an object. (scale or balance) Length measure of distance (ruler, meter stick) Temperature - measure of the average amount of Kinetic energy in particles. Thermometer] Volume - the amount of space an object takes up (beaker, graduated cylinder 2 Measurements V= m/v divide Dem/v Density- amount of mass in a given space D-mass/ volume What is Chemistry? Chemistry Science that investigates and explains Properties of matter Matter - Anything that has muss and takes up Spare Not Matter - Heal, electricity, Sound, time microwaves Mass - The amount of matter in a given object (number/weight of atoms) Physical Properties - Characteristics that can be observed or measured without any change in identity. [Solubility, melting point, color) Physical change - change in matter that does not involve a change in the identity of Substance. (boiling, freezing, evaporating). Chemical properties - Those that can easily be observed when There is a change in the composition of the Substance. describe how it reacts] Chemical charge charge of 1 or more sukshunces into a new substance Atoms become rearranged to form new compounds [burn, rot, oxides] Signs of Chemical change -​ New Substance forms. -​ odor given off -​ Color Change -​ precipitate forms -​ Has given off -​ Heat or light given off -​ Temperature change Classifying Matter  pure substance made entirely of only one hand of matter Ex: pure sugar, pure water, carbon dioxide, gold - [elements and compounds are pure Mixture a combustion of two or more substances in which the basic identity of each substance.Is not changed. (Salt water and salad dressing.) Elements are pure matter Element - simplest form of matter, male of only one kind of atom. Cannot be broken down simpler. Table has 1 118 - elements band with other elements to form millions of compounds 92 elements occur naturally on earth 1-92. The others are made Synthetically (man-made). 93-118 Compounds are Pure Matter Compounds a chemical combination of two or more different elements. Joined together in a fixed ratio (H₂O, CO₂) Compounds hold different properties than the clements that make them up. Can be separated chemically. Pure water is always 112% Hand 88.8% O by mass Mixture types mixture Heterogeneous - different does not have a uniform Composition, individual comports remain distinct (trail mix, Salt and pepper) Mixture  Homogeneous "alike", Same throughout, a Solution (tea, Salt water. gasoline)" Alloy - Solid mixture that contains different metals. (steel- mixture of iron, carbon, chromium, manganese, nickel, molybdenum Mixtures can be separated physically because there is no interaction (bonding) belucen different Substances. Solutions Solute Substance being dissolved (sugar, Sult Smaller amount.) Solvent - Substance doing the dissloving (water or Other liquid, Larger amount. When water is the solvent we call the solution an aqueous solution... water is considered the "universal Solvent", dissolving more substance than any other liquid. Periodic table of Elements *The PT organizes elements based on their chemical properties Many element Symbols are Latin (K. Me, Fe, Cu, Ag, Sn) W is German Period-horizontal row of elements on periodic table. 7 total Group Vertical column of elements on the periodic table (Family) 18 total * Group Names properties change as you move across a period (row) Properties are very similar for charmits in the some gea(Galum) Group 1 Alkali metals Group 2 = Alkaline earth metals Group 3 11: Transitional metals Group 17: Halogens Group B. Noble gasses  Classifying Elements-188 total. 2 elements are liquid(mercury & bromine) - Il elements are gas at room temp. Elements after Uranium 92 are synthetic elements. Man made Metals Have luster, Conduct heal stod electricity, Malleable and ductile, Solid at room temperature (Not mercury) Left of zigzag line. All physical properties Non-metals No Luster (dull), Not malleable (brittle) or ductile, Do not conduct heat or electricity, Very common on Earth (carbon. Oxygen, nitrogen) Lower melting points, Most gasses at room temperature. Right zig zag line Metalloids Properties of both metals and nonmetals. Border Zig-Zag line Semiconductors-Conducts electricity a little. Silicon in computers? Atomic Structure Atoms contain 3 subatomic particles. Electrons - negatively charged particles found outside the nucleus. - Mass of zero Protons- positively charged particles found inside the nucleus. - Mass of 1 amu Neutron-neutral (no electrical charge) particles inside the nucleus. -Mass of 1 amu Atomic terms Macters small, dance, positively charged center of an atom. Contains protons and neutrons Atomic number of protons in the nucleus for each atom of that element. (this is the atom's identity) Mass number the sum of protons and neutrons in the nucleus of an atom. (Rounded atomic mass) Atomic mass the weighted average of all the naturally occurring of an element (atomic mass unit) amu Atomic Mass and Isotopes Atomic mass-The weighted average of all the naturally Occurring isotopes of an element. (atomic mass weight, unit amu) Isotope atom of an element with same number of protons but different number of neutrons Chemically alike, but have Different mass) Cathon-12 99% (12×0.99)+(15/001) Carbon 13 1% 6:11.88 +0.13 Atomic weight = 12.01 Electrons and Energy Sublevels Quantum theory describes mathematically the wave properties of electrons and other very small particles Electrons have wavelike properties. Electrons velocity or position cannel be determine Orbitals indicate the probable location of electrons. Orbitals ore 3-D repon suremanding nucleus. Where we find electrons. Orbitals. S. P. D. F Sublevel division with an energy level 4 sublevels: s p d f (Increasing energy) First energy level has one sublevel (1s) Second energy level has two sublevels (2s and 2p) Third energy level has three sublevels (3s, 3p,and 3d). Fourth energy level has 4 sublevels. S level-can hold 2 P level can held 6 D level-can hold 10 F level- can hold 14 Electrons fill the lowest energy levels first. Shape of modern periodic table is a result of the Or the order in which electrons Fill sublevel and orbitals Group 1 and 2 = S Block Group 13-18 = p block Group 3-12 d block Inner transition elements = f block up dow Electron Configuration Electron Configuration the arrangement of electrons in on atom Aufbau principle States that an electron will alway occupy the lowest energy sublevel available Example 4s orbital fills with electrons prior to 3d