General Chemistry: Finals Reviewer PDF

GENERAL CHEMISTRY: FINALS REVIEWER LESSON 1: Periodic Table ▪ Moseley precisely organized elements by using an electron gun to shoot them, which Periodic Table...

GENERAL CHEMISTRY: FINALS REVIEWER LESSON 1: Periodic Table ▪ Moseley precisely organized elements by using an electron gun to shoot them, which Periodic Table gave off x-rays - a useful tool for organizing the known The Modern Periodic Table elements. Arranged into increasing atomic number from History of the Periodic Table left to right. ❖ 1808 IUPAC ( International Union of Pure and Applied John Dalton Chemistry) – updating and monitoring the table of ▪ He theorized that atoms of the same elements. element are the same. Columns are called groups. ▪ Assigned atomic weights to the first Rows are called periods. elements discovered. Elements in the same group have similar ▪ 20 elements in the early version of periodic properties. table Non-metals are to the right. ❖ 1817 Metals are to the left and center. Johann Dobereiner PERIOD OR SERIES - horizontal rows of the ▪ Law of Triads – he grouped the elements periodic table into sets of three. GROUPS OR FAMILIES - vertical columns of the ▪ This idea occurred when he found periodic table strontium's atomic weight between calcium and barium. ❖ 1864 John Newlands ▪ Law of Octaves - when elements are arranged by increasing atomic mass, every eighth element exhibits similar characteristics ▪ Grouped the elements into 8 – increasing mass number ❖ 1869 Dmitri Mendeleev ▪ Father of Modern Periodic Table ▪ PERIODICITY - refers to the repeating patterns in the chemical and physical properties of elements when arranged by increasing atomic mass. ▪ Mendeleev arranged 63 elements by atomic mass, grouping them by similar chemical and physical properties. ▪ There are gaps for undiscovered elements ❖ 1913 Henry Moseley ▪ X – RAY EXPERIMENTS - rearranged the elements by increasing atomic number instead of atomic mass.  GENERAL CHEMISTRY: FINALS REVIEWER Classification of Elements (Property) ❖ Representative Elements - The s and p block elements Periodic Trends - are systematic variations in the properties of elements across the periodic table. ❖ Metallic Property - is related to an atom's ability to lose an electron TREND o top to bottom = increases ❖ Metals o left to right = decreases Metals easily lose electrons to form positive ions (cations) and have low electronegativity, typically 2.2 and below PROPERTIES OF METALS ▪ Conductivity: Good conductors of heat and electricity, thanks to free-moving electrons. ▪ Malleability: Can be hammered or rolled into thin sheets without breaking. ▪ Luster: Have a shiny appearance, reflecting light from smooth surfaces. ▪ Ductility: Can be stretched into wires ❖ Non-Metallic Property without breaking. - are characteristics of elements that easily gain ❖ Non-metals electrons, resulting in poor conductivity, Nonmetals are nonconductors of heat and are brittleness, dull appearance, and high electron acceptors, forming negative ions electronegativity (anions). They have high electronegativity, ranging from 2.0 to 4.0. TREND ❖ Metalloids o top to bottom = decreases Metalloids have properties that are o left to right = increases intermediate between metals and nonmetals, with electronegativity ranging from 1.8 to 2.1 Classifications of Elements (Orbital Being Filled Up) ❖ Atomic Size - is half the distance from the nucleus to the outermost shell.  GENERAL CHEMISTRY: FINALS REVIEWER TREND ❖ Electronegativity - is the tendency of an atom to attract electrons o top to bottom = increases when bonding with another atom o left to right = decreases TRENDS o top to bottom = decreases o left to right = increases ❖ Ionization Energy - is the energy required to remove the most loosely bound electron from an atom to form a cation TREND o top to bottom = decreases o left to right = increases ❖ Electron Affinity - is the energy released when an atom gains an LESSON: Biomolecules electron to form an anion Biomolecules TREND - Lipids, nucleic acid, carbohydrates, and proteins o top to bottom = decreases - Important for the survival of the living cells o left to right = increases Monomers - Monomers are small, basic molecules that bond with other monomers to form larger, more complex molecules called polymers. ❖ Carbohydrates Carbohydrates are organic compounds made of carbon, hydrogen, and oxygen, serving as a  GENERAL CHEMISTRY: FINALS REVIEWER primary energy source, and include sugars, starches, and fibers Monosaccharide – monomer of carbohydrate LESSON 2: Lewis Structure ▪ Ex. glucose, fructose, or galactose Chemical Bonding Disaccharide - is a carbohydrate made up of two monosaccharide molecules bonded - A force that holds atoms of elements together together to form a compound ▪ Ex. sucrose (glucose + fructose), lactose Valence Electron (glucose + galactose), or maltose (two glucose molecules) - electrons that reside in the outermost shell of Polysaccharide - is a complex carbohydrate an atom made up of many monosaccharide units linked together ▪ Ex. starch, glycogen, and cellulose ELEMENTS PRESENT: Carbon, hydrogen, and oxygen ❖ Lipids Lipids are fatty compounds essential for energy storage, structure, protection, and signaling. Glycerol and fatty acids are the basic building blocks of many lipids. ▪ Fatty acids are long hydrocarbon chains with a carboxyl group at one end. Identifying Valence electrons of an atom (By ▪ Glycerol is a three-carbon molecule that looking at the outermost shell of the element) binds with three fatty acids to form EX. OXYGEN ( 1s²2s² 2p⁴ ) triglycerides (fats and oils). ELEMENTS PRESENT: Carbon, hydrogen, oxygen, - 2s² 2p⁴ is in the phosphorus, and nitrogen second shell of the atom which is ❖ Protein Oxygen’s outermost are large, complex molecules made up of amino shell. acids - 6 is the valence Amino acids – monomer of proteins electron of oxygen are composed of long chains of amino acids Gilbert Newton Lewis ELEMENTS PRESENT: Carbon, hydrogen, oxygen, phosphorus, and nitrogen - Formulated the Octet Rule ❖ Nucleic Acid - He proposed that atoms combine to Nucleic acids are large biomolecules that store achieve a more stable electron and transmit genetic information in living configuration. organisms. Nucleotides - the monomers of nucleic acids Octet Rule “Rule of Eight” ELEMENTS PRESENT: Carbon, hydrogen, oxygen, and nitrogen ▪ Atoms react to acquire a full set of eight valence electrons, similar to the electron configuration of noble gases.  GENERAL CHEMISTRY: FINALS REVIEWER Lewis Electron Dot Structure - It consists of the element’s symbol Types of Ions based on the number of Atoms surrounded by dots, where each dot represents a valence electron. IONS MONOATOMIC ION POLYATOMIC ION -are single atoms that -consist of two or more can be cations (positive) atoms that carry a charge or anions (negative), due to the overall loss or formed by the loss or gain of electrons. gain of electrons. Neon (1s²2s² 2p⁶) - it is STABLE because it has 8 valence electrons (octet rule) Writing Lewis Symbol - Dots are not paired until all sides have a single dot. - Each side can hold a maximum of two dots. EXAMPLE: Nitrogen: 5 valence electrons Transferring Electrons - One way atoms achieve a total of eight electrons in their outermost energy level Types of Ions based on Charges IONS Losses ē Gains ē CATION ANION