FINAL EXAM REVIEW (Chapters #1-6)

Defining Chemistry.... ✴ Chemistry is the study of the composition of matter and the changes that matter undergoes ✴ Known as the “central science” ✴ Matter is anything that has mass and occupies space ✴ Trees, water, buildings, air, etc.

Chemistry has 5 specific areas of study: ✴ Organic chemistry ✴ Inorganic chemistry ✴ Biochemistry chemistry ✴ Analytical chemistry ✴ Physical chemistry

Organic Chemistry ✴ Defined as the study of all chemicals containing carbon ✴ Most chemicals that are found in organisms contain carbon

Inorganic Chemistry ✴ Defined as the study of chemicals that, in general, do not contain carbon ✴ Many inorganic chemicals are found in non- living things ✴ Rocks ✴ Bones

Biochemistry ✴ Defined as the study of processes that take place in living organisms ✴ Muscle contraction, digestion, metabolism

Analytical Chemistry ✴ The area of study that focuses on the composition of matter ✴ Measuring the level of carbon dioxide in the atmosphere ✴ Used to assure the safety and quality of food, pharmaceuticals, and water

Physical Chemistry ✴ The area of chemistry that deals with the mechanism, rate, and energy transfer that occurs when matter undergoes change ✴ Rate of photosynthesis in trees

Inorganic chemistry Organic chemistry Analytical chemistry Physical chemistry Biochemistry

States of Matter There are three states of matter: ✴ Solid ✴ Definite shape and volume ✴ Liquid ✴ Indefinite shape and a definite (fixed) volume ✴ Gas ✴ Indefinite shape and indefinite volume (Takes the shape of the container it is in)

Extensive vs. Intensive Properties ✴ An extensive property is a property that depends on the amount of matter in a sample ✴ The mass of an object is a measure of the amount of matter the object contains ✴ The volume of an object is a measure of the space occupied by the object

Extensive vs. Intensive Properties ✴ An intensive property is a property that depends on the type of matter in a sample, not the amount of matter ✴ Density, melting point, boiling point, color, hardness

Classifying Changes in Matter ✴ Physical change ✴ The appearance of the matter may change but the composition does not ✴ Melt, boil, freeze, condense, break, split, grind, crush ✴ Chemical change ✴ A change that produces matter with a different composition than the original matter ✴ Burn, rot, rust, decompose, explode, corrode

Classification of Matter ALL matter can be classified as either a pure substance or a mixture

Mixtures ✴ A mixture is a blend of two or more types of matter, each of which retains its own identity and properties ✴ Chicken noodle soup ✴ Air ✴ Salad dressing ✴ Lucky charms

Homogenous vs. Heterogenous Mixtures ✴ Homogenous mixture (solution) ✴ Composition is uniform throughout the mixture ✴ Air, salt water, vinegar (water + acetic acid), stainless steel (Fe,Cr, and Ni) ✴ Heterogenous mixture ✴ Composition is not uniform throughout the mixture ✴ Chicken noodle soup, Italian salad dressing ✴ Based on the distribution of their components, mixtures can be classified as:

✴ A homogeneous mixture can sometimes look the same ✴ They appear the same until light is passed through ✴ In a colloid, the light is scattered–Tyndall Effect ✴ Examples: Milk, orange juice (no pulp), pudding Colloid

Pure Substances

ATLANTIC vs. PACIFIC RULE (Determining the number of significant figures)

Atlantic = decimal point is absent Count the significant figures starting with the first non-zero digit on the right Pacific = decimal point is present Count the significant figures starting with the first non-zero digit on the left

Addition and Subtraction with Significant Figures ✴ The answer should be rounded to the same number of decimal places (not digits) as the measurement with the least number of decimal places Examples: meters meters meters = meters – meters =

✴ Round the answer to the same number of significant figures as the measurement with the least number of significant figures Multiplying and Dividing with Significant Figures Examples: meters x 0.34 meter = meters x 0.70 meter = meters 2 ÷ 8.4 meters = meter 2 ÷ meter =

✴ There are six SI base units SI Base Units QuantitySI base unitSymbol Lengthmeterm Masskilogramkg TemperaturekelvinK Timeseconds Amount of substancemolemol Volumemeter cubedm3m3

Commonly Used Metric Prefixes PrefixSymbolFactor kilok10 3 = (1000) hectoh10 2 = (100) decaD10 1 = (10) gram, liter, meterg, L, m decid10 -1 = (1/10) centic10 -2 = 1/100) millim10 -3 = (1/1000)

Density ✴ Density is the ratio of the mass of an object to its volume ✴ The relationship between an object’s mass and its volume tells you whether it will float or sink mass volume Density =

Properties of Subatomic Particles ParticleSymbol Relative charge Relative mass (mass of proton = 1) Actual mass (g) Electrone–e– 1–1/  10 –28 Protonp+p  10 –24 Neutronn0n  10 –24 The table below summarizes the properties of these subatomic particles:

Atomic Number The atomic number identifies the element (like a social security number identifies you) ✴ An element’s atomic number is the number of protons in the nucleus of an atom of that element ✴ Atomic number = protons

Mass Number The total number of protons and neutrons in an atom is called the mass number ✴ Mass number = protons + neutrons

Isotopes Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons ✴ Same number of protons, different mass

Principle Quantum Number (n) ✴ Indicates the main energy level (shell) occupied by the electron ✴ These numbers are assigned the values n = 1, 2, 3, 4, 5, 6....

Angular Momentum Number (l) ✴ Indicates the shape of the orbital ✴ l = s,p,d,f ✴ More commonly referred to as the sublevel (subshell)

Sublevel (subshells) s-subshell contains 1 orbital p-subshell contains 3 orbitals d-subshell contains 5 orbitals f-subshell contains 7 orbitals **Each orbital can hold a maximum of 2 electrons (2e - )

RULES FOR ELECTRON CONFIGURATION & ORBITAL NOTATION 1. Aufbau principle ✴ An electron occupies the lowest energy orbital that can receive it ✴ Fill the electrons lowest to highest energy 2. Hund’s Rule ✴ Orbitals of the same energy must be occupied by one electron before it can be occupied by two electrons 3.Pauli-Exclusion principle ✴ Each orbital can only hold 2 electrons with opposite spins

Increasing energy 1s 2s 3s 4s 5s 6s 7s 2p 3p 4p 5p 6p 3d 4d 5d 7p 6d 4f 5f

The elements in Group 1A are called alkali metals The elements in Group 2A are called alkaline earth metals. Groups of the Periodic Table

The nonmetals of Group 7A are called halogens The nonmetals of Group 8A are called Noble Gases

Representative Elements Elements in Groups 1A through 7A (s and p blocks) are often referred to as representative elements S and P Blocks! They display a wide range of physical and chemical properties.

More positively charged protons than negatively charged electrons, the ion has a net positive charge The charge for a cation is written as a number (number of electrons lost) followed by a plus sign Metals tend to form cations Cation (Positively charged atom)

Anion (Negatively Charged atom) More negatively charged electrons than positively charged protons, the ion has a net negative charge The charge for an anion is written as a number (number of electrons gained) followed by a minus sign Nonmetals tend to form anions

PERIODIC TRENDS Chapter 6.3

Atomic Size The size is expressed as an atomic radius

In general, atomic size increases from top to bottom within a group, and decreases from left to right across a period

Ionization Energy Ionization energy is the energy required to remove an electron from an atom Ionization energy tends to decrease from top to bottom within a group and increase from left to right across a period

Ionic Size Cations are always smaller than the atoms from which they form Anions are always larger than the atoms from which they form

Electronegativity Electronegativity is the ability of an element to attract electrons Low values = low ability to attract electrons (donates electrons to form cations) High values = high ability to attract electrons (gains electrons to form anions)

Electronegativity values decrease from top to bottom within a group and increase from left to right across a period