Chemistry PDF - Periodic Table and Elements

Mendeleev blocks of the periodic table are made an important discovery arranged in about the elements ROWS...

Mendeleev blocks of the periodic table are made an important discovery arranged in about the elements ROWS PERIOD/SERIES Periodic Law which states, When arranged by COLUMNS increasing atomic number, the FAMILY/GROUP chemical elements display a regular and repeating pattern of ELEMENT KEY chemical and physical properties. provides the basic information about each element Valence Electrons are those electrons found on the outside edge of the atom, farthest away from the nucleus. CHEMICAL ATOMIC ATOMIC ELEMENT SYMBOL MASS NUMBER NAME. An atom will have from 1 to 8 valence electrons, abbreviated as Ve-. Valence electrons are used to bond to other Group IA – alkali metals atoms to form COMPOUNDS. Forms a “base” (or alkali) when reacting with Determining the number of Valence water (not just dissolved!) Electrons Group 2A – alkaline earth metals GROUP NUMBER the element is in. Also form bases with water; do not dissolve well, hence “earth metals” Group 7A – halogens Means “salt-forming” Metals Metalloids or Semi-metals Nonmetals Have a shiny surface. They have characteristics of Dull Malleable both metals and nonmetals. Not shiny/can’t be polished. Can be hammered thin. They are shiny but brittle. Brittle Ductile They are semiconductors: Break easily…cannot be elements that have conduction Can be stretched (wire) hammered thin. capacities between nonmetals Good Conductors Poor/non-conductors and metals. Allow heat and electricity to Limited or no flow of heat or What are our most important flow through easily. electricity through them. semiconductors? They are mostly solids at Silicon, Germanium, and (also called insulators). room temp. Arsenic. Some are solid, several are What is one exception? gases, and BROMINE is a Mercury (Hg) is a LIQUID liquid. metal!  Elements can be sorted into 4 different groupings based on their electron configurations: Noble gases Transition metals are the elements in Group 8A (also called are in the “B” columns of the periodic table Group18 or 0) Electron configuration has the Previously called “inert gases” because outer s sublevel full, and is now they rarely take part in a reaction; very filling the “d” sublevel stable = don’t react A “transition” between the metal Noble gases have an electron area and the nonmetal area configuration that has the outer s and p Examples are gold, copper, silver sublevels completely full Representative elements Inner Transition are in Groups 1A through 7A Metals are located below the main body of Display wide range of properties, thus a the table, in two horizontal rows good “representative” Electron configuration has the Some are metals, or nonmetals, or outer s sublevel full, and is now metalloids; some are solid, others are filling the “f” sublevel gases or liquids Formerly called “rare-earth” Their outer s and p electron elements, but this is not true configurations are NOT filled because some are very abundant  inversely proprtional Atomic Radius Ionization Energy Electron Affinity Electronegativity is the distance from the energy needed to Electron affinity is the how easily an atom center of the nucleus to remove an electron energy change that accepts an electron the “edge” of the electron from a neutral atom ( occurs when an atom Electronegativity is in gaseous state) gains an electron (also a measure of an cloud. measured in kJ). atom’s attraction half the distance between the for another atom’s nuclei of 2 bonded atoms. measured in electrons. picometers (pm) (1 x 10-9 m) It is an arbitrary scale angstroms (Å) (1 x 10-10 m) that ranges from 0 to 4. The units of trend electronegativity are Paulings. increses up to down trend Generally, metals are decreases up to down electron givers and have decrease left to right low electronegativities. Nonmetals are electron With each step down the takers and have high family, we add an entirely new electronegativities. Principle Energy Level PEL to the electron cloud, making the atoms larger with each step. Each step adds a proton and an electron (and 1 or 2 neutrons). The nucleus is more positive and the electron cloud is more negative. The increased attraction pulls the cloud in closer to the nucleus, making atoms smaller as we move from left to right across a period. e-sheilding Metallic Character The most reactive The Octet Rule metals are the largest when more PEL is the quantum level since they are the best The “goal” of most added reacitibity of a metal electron givers. atoms (except H, inner levels sheild which tends to lose Li and Be) is to outer levels from electrons The most reactive nonmetals are the have an octet or nucleas attraction group of 8 electrons smallest ones, the best electron takers. in their valence The effective nuclear attraction energy level. for these outer electrons is less, and so the outer electrons are When an atom gains an electron, it becomes Atoms that have gained or less tightly held. lost electrons are called ions. negatively charged (more electrons than protons This makes it easier to remove ) and is called an anion. some of these e- when bonding to other atoms. In the same way that nonmetal atoms can gain electrons, metal atoms can lose electrons. They become positively charged cations.  A molecular formula types of ions shows the exact number of atoms acid can be defined as a substance of each element in the smallest that yields hydrogen ions unit of a substance. (should have hydro at the begining) (and “ic`’ at the end) monatomic ion polyatomic ion An empirical formula shows the simplest whole-number base contains only contains more one atom than one atom ratio of the atoms in a substance. can be defined as a substance that yields hydroxide ions (contains OH-) ( name it by ionic compounds adding hydroxide after the consist of a combination of cations element) and anions. The formula is usually the oxoacid same as the empirical formula. is an acid that contains hydrogen, The sum of the charges on the oxygen, and another element. The most reactive metals (green) cation(s) and anion(s) in each (name it according to the third and the most reactive nonmetals formula unit must equal zero. element) (blue) combine to form ionic compounds. oxanion when we remove hydrogen so it becomes negative Hydrates are compounds that have a specific number of water molecules attached to them. (traps water, doesnt contain it in them) (name the compound , write the prefix of the water molocule then a (.) then the hydrate)