Unit 4 - The Periodic Table

Ion

Definition a charged atom or group of atoms formed by the addition or removal of one or more electrons Key Context In stable atoms the number of protons (positive charges) are equal to the number of electrons (negative charges). Sometimes atoms gain or lose electrons and then the number of protons and electrons differ in an atom. When this happens the atom is called an _______. Greek/Latin Etymology from Greek root ion, meaning "go"

Ionic Bond

Definition a chemical bond in which one atom gives up electrons (cation) to another atom that gains the electrons (anion); results from a difference in electronegativity greater than 1.7 Key Context In an _______________, electrons are transferred from one atom to another. This results in the formation of positively charged ions (cations) and negatively charged ions (anions) which are attracted to each other.

Conductor

Definition a material that allows electricity, heat or sound to pass through it easily Key Context Electrons can pass through some materials relatively easily, while they have a much more difficult time passing through other materials. Materials that allow electrons to flow relatively easily are known as __________________. Many metals such as copper and iron are good _________________ of electricity. Greek/Latin Etymology Prefix con- meaing "with", Latin root duc- meaning "lead"

Atomic Radius

Definition a suffix combined with the name of an element to designate polyatomic ions containing more oxygen atoms than similar ions Key Context Sulfate (SO42-) is a polyatomic ion. It contains more oxygen atoms than sulfite (SO32-). This also means that the sulfur in SO42- is in a higher oxidation state (+6) than the sulfur in SO32-(+4).

Shielding Effect

Definition decreased attraction of electrons away from the nucleus Key Context Due to the ______________________, successive electron shells surrounding the atomic nucleus result in decreasing attraction of electrons to the nucleus. The shielding effect explains some properties of elements based on their atomic number and electron shell configuration. Greek/Latin Etymology From the Old English scield, meaning "protector" or "defense" and from the Latin effectus, meaning "to bring about"

Transition Metals

Definition elements that are made by filling either the d or f orbitals with electrons Key Context The d block elements are _______________________ formed by filing the d orbital with electrons. The d orbitals can accommodate 10 electrons, which is why there are 10 transition metals for each period. Additionally, the elements made from filling the f orbitals with electrons are known as the inner transition metals. The f orbitals can hold 14 electrons, which accounts for the 14 inner transition metals for each period in the f block.

Nonmetals

Definition elements that are poor electrical conductors and tend to accept electrons easily Key Context A basic way to divide elements in the periodic table is into metals, _________________, and metalloids. ________________ atoms typically gain one or more electrons to form negative ions (anions). The _________________ elements are found on the upper right side of the periodic table. Greek/Latin Etymology Latin stem metallum meaning "product of a mine"; Latin prefix non- meaning "not"

Metals

Definition elements that give up electrons easily, are malleable and ductile, and are good electrical conductors Key Context A basic way to divide elements in the periodic table is into ____________, nonmetals, and metalloids. ____________ atoms tend to give up one or more electrons to form positive ions (cations). The ____________ elements are found on the left side of the periodic table. Greek/Latin Etymology Latin stem metallum meaning "product of a mine"

Metalloids

Definition elements that lie between the metals and the nonmetals on the periodic table; these element exhibit both metallic and nonmetallic properties Key Context A basic way to divide elements in the periodic table is into metals, nonmetals, and ________________. The metalloids lie on a diagonal division line between the metals and nonmetals and can demonstrate properties of both. Typical metalloids are boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te), polonium (Po), and astatine (At). Greek/Latin Etymology Greek suffix -oid meaning "like"

Period

Definition one of the horizontal rows in the periodic table Key Context There are seven ____________ in the current periodic table. As you travel across one of the ____________, the atomic number and number of valence electrons increase. Greek/Latin Etymology Greek/Latin stem periodos meaning "circuit"

Periodicity

Definition recurring pattern of similar chemical and physical properties of elements which are close to each other in the periodic table Key Context Mendeleev placed elements in the periodic table according to their properties. He noticed that the elements displayed __________________. That is, the elements in each row shared some properties, as did those elements in each column. This periodicity made it possible to predict the properties of undiscovered elements. Greek/Latin Etymology Greek/Latin stem periodos meaning "circuit"

Malleability

Definition the ability of a material to be beaten into a thin sheet or to be shaped without breaking Key Context Some metals are ________________; they can be easily shaped without breaking. For example, heated iron is _______________ and can be pounded to form horseshoes. Greek/Latin Etymology Latin stem malleus meaning "hammer"

Ductility

Definition the ability of a material to be stretched into a wire without breaking Key Context Some metals are _______________. They can be stretched into a wire without breaking. For example, copper wires are made by extending a piece of copper for form fine wires. Greek/Latin Etymology Latin stem ductilis meaning "to lead"

Ionic Radius

Definition the distance between an ion's nucleus and its outer electrons (those electrons remaining after the valence electrons have been lost) Key Context __________________ increases as you move down the periodic table. When more energy levels are used, the valance electrons are located further from an ion's nucleus. Greek/Latin Etymology from L. radius "staff, spoke of a wheel, beam of light,"

Actinide Series

Definition the elements following actinide (Ac, atomic number 89) that fill the 5f block from period 7 on the periodic table Key Context The elements in the _____________________ are chemically and physically related to the element actinium (Ac), atomic number 89. These elements belong between actinium (Ac) and rutherforium (Rf) in the periodic table and are all found to be radioactive. Commonly, they are displayed in the second of two rows placed below the main body of the periodic table. Greek/Latin Etymology Greek stem aktino- meaning "beam, ray"

Lanthanide Series

Definition the elements following lanthanum (La, atomic number 57) that fill the 6f block from period 6 on the periodic table Key Context The elements in the ________________________ are chemically and physically related to the element lanthanum (La). These elements are found inserted between lanthanum (La) and hafnium (Hf) in the periodic table. Commonly, they are found displayed in the first of two rows placed below the main body of the periodic table. Greek/Latin Etymology Greek stem lanthanein meaning "to escape notice"

Alkali Metals

Definition the group 1 (Group IA) elements: potassium (K), sodium (Na), lithium (Li), rubidium (Rb), cesium (Cs), and francium (Fr) Key Context The ________________ comprise group 1 of the periodic table. Each has only one electron in its outermost energy level. These elements are highly reactive, silver-colored metals. They typically have low melting and boiling points.

Halogens

Definition the group 17 (Group VIIA) elements; consists of fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At) Key Context The group of elements that make up the ______________ are found in group 17 on the periodic table. They are nonmetals with one electron short of a full outer p orbital. These elements are highly reactive, and, depending on the element, can be a solid, a liquid, or a gas at standard conditions. In their elemental form, the ______________ are diatomic molecules: F2, Cl2, Br2, I2, At2. They are highly electronegative.

Alkaline Earth Metals

Definition the group 2 (Group IIA) elements: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra) Key Context The __________________________ comprise the metals in group 2 of the periodic table. Each of these elements has two electrons in its outermost energy level. These elements are reactive, silver-colored metals that tend to react with halogens to form ionic salts. They typically have higher melting and boiling points than the alkali metals.

Ionization Energy

Definition the minimum energy required to remove an electron from the ground state of an atom (also known as the binding energy) Key Context The ________________________ of an atom is the energy required to remove an electron and is usually measured in electron volts (eV). Since electrons are involved in chemical bonding, the ________________________ is often an indicator of the reactivity of an element. Elements with low ________________________ such as sodium tend to form cations because it requires less energy to remove one of their outer electrons. Greek/Latin Etymology Greek root energos meaning "active, working"

Ionic Size

Definition the size of an ion in a crystal lattice Key Context The ______________ is a measure of the size of a particular ion or the space that its nucleus and electrons take up. One way to determine the ionic size is to measure the ionic radius when the ion is in a crystalline lattice.

Electronegativity

Definition the tendency of an atom to attract electrons and acquire a negative charge Key Context Elements with high ________________________ values are more reactive. The polarity of a bond can be determined by taking the difference between the electronegativities of two atoms. Greek/Latin Etymology Latin root negare meaning "oppose"

Periodic Trend

Definition the tendency of certain elemental properties to increase or decrease as one moves in a certain direction along the periodic table Key Context The periodic table is arranged in order of increasing atomic number and in relation to the electron configuration of elements. Because elements with the same number of valence electrons exhibit similar properties and because elements generally gain electrons and mass as one moves down the periodic table, certain patterns emerge in the properties of elements. Greek/Latin Etymology Prefix peri- meaning"around"

Groups

Definition vertical columns of elements (families) on the periodic table with similar valence electron configurations and similar properties Key Context _____________, or families, of elements in the periodic table share many similar physical and chemical properties. These properties are the result of the similar number of valence electrons among elements of a group or family. For example, elements in group 1 their outer electron shells. This affects the chemical behavior of this family of elements.

Families

Definition vertical columns of elements (groups) on the periodic table with similar valence electron configurations and similar properties Key Context ______________, or groups, of elements in the periodic table share many similar physical and chemical properties. These properties are the result of the similar number of valence electrons among elements of a family or group. For example, elements in group 1 each have only one electron in their outer electron shell. This affects the chemical behavior of these group 1 elements. Greek/Latin Etymology Latin stem familia meaning "a household"