Periodic Properties of the Elements & Metallic Structure

Flashcards covering key concepts related to the periodic table, periodic trends, atomic and ionic properties, the metallic model, and properties of major element groups.

Periodic Table Organization

Organized into columns and rows based on increasing atomic number, providing information about electron arrangement.

Periodic Table Row Number

Corresponds to the outermost energy level of an atom's electrons.

Periodic Table Column Number

Corresponds to the number of valence electrons.

Valence Electrons

Electrons located in the outermost shell of an atom.

Periodic Properties of the Elements

General trends like atomic/ionic size, ionization energy, and electron affinity.

Atomic Radius

The distance from the nucleus of an atom to the outermost region of its electron cloud, serving as a measure of atom size.

Atomic Radius Trend (Left to Right)

Decreases across a period due to increasing nuclear attraction.

Atomic Radius Trend (Top to Bottom)

Increases down a group due to the addition of energy levels.

Anion

A negatively charged ion, which is larger than its neutral atom due to increased electron-electron repulsion.

Cation

A positively charged ion, which is smaller than its neutral atom due to increased electron-proton attraction.

Ionic Radius Trend (Top to Bottom)

Increases down a periodic group.

Ionisation Energy (Ei)

The minimum energy required to remove an electron from the ground state of an atom in the gas phase; always a positive value.

First Ionization Energy (I )

The energy required to remove one electron from a neutral atom in the gas phase.

Second Ionization Energy (I )

The energy required to remove an additional electron from an ion in the gas phase.

Factors Affecting Ionization Energy

Nuclear charge (higher charge, higher Ei) and distance of the electron from the nucleus (farther, lower Ei).

Ionization Energy Trend (Up a Group)

Increases because electrons are removed from lower energy levels (closer to the nucleus).

Ionization Energy Trend (Across a Period)

Increases because electrons are removed from the same energy level but the nuclear charge increases.

Electron Affinity (E.A.)

The energy change (released or absorbed) when an electron is added to a gaseous atom.

Negative Electron Affinity

Indicates that an atom readily accepts an electron, releasing energy, and signifying a stronger attraction for an extra electron.

Positive Electron Affinity

Indicates that adding an electron requires energy, meaning the process is not spontaneous.

Metals

Elements that conduct electricity and heat well, are malleable, shiny, and mostly solid at room temperature.

Metallic Model

Describes metals as a giant three-dimensional structure of positive ions (cations) within a 'sea' of free, delocalized electrons.

Electron Sea

Formed by the contribution of valence electrons from each atom in a metal, allowing electrons to move freely.

Delocalized Electrons (in Metals)

Valence electrons in a metal that are not unclear which specific nucleus they belong to, effectively being shared by many positive ions.

Metallic Bonding

The electrical attraction between positive ions and the negative electron cloud in a metal.

Malleability (of Metals)

The property allowing metals to be hammered into thin sheets, due to layers of atoms sliding over each other without breaking the structure.

Electric Conductivity

The ability to conduct an electrical current, which in metals is due to the directed flow of mobile electrons.

Alkali Metals (Group 1)

Highly reactive metals used in batteries and photoelectric cells; reactivity increases down the group.

Alkaline Earth Metals (Group 2)

Moderately reactive metals, reacting with water (slowly) and acids/halogens.

Transition Metals

Elements found in the middle block of the periodic table, known for forming colored compounds and often acting as catalysts, with variable oxidation states.

Non-Metals

Elements that generally do not conduct electricity (except carbon) or heat, are brittle, and can exist as gas, liquid, or solid at room temperature.

Noble Gases (Group 18)

Elements with very low (almost inert) reactivity, existing as monoatomic gases, and used in lighting and balloons.