Changes and Properties of the Periodic Table

Flashcards covering the historical evolution of the periodic table, classification of elements, electronic configuration blocks, and periodic properties based on the lecture transcript.

Antoine Lavoisier (1790)

Compiled $30$ elements commonly used at the time and replaced their names when arranging them in a table.

Jacob Berzelius (1803)

Ordered the elements known at the time in alphabetical order.

Johann Döbereiner (1829)

Classified elements into triads based on characteristics shared between them.

John Newlands (1865)

Ordered the elements in groups of $8$ members according to the Law of Octaves.

Julius Lothar Meyer (1869)

Established an increasing order of elements based on their atomic masses.

Dimitri Mendeleyev (1869)

Ordered $63$ elements according to their atomic masses, grouped them in rows, and associated columns with similar atomic properties.

Henry Moseley (1913)

Proposed that the ordering of the periodic table should be according to the atomic number in increasing form.

Hydeto Enyo (2016)

Proposed adding a new row of chemical elements to start the eighth period.

International Union of Pure and Applied Chemistry (2018)

Updated the Periodic Table to the current version on December $1$.

Metals

Good conductors of heat and electricity that are ductile, malleable, lustrous, have high melting points, and form cations.

Non-metals

Poor conductors of heat and electricity that are opaque, non-ductile, have low melting points, and form anions.

Metalloids

Substances that present intermediate properties between metals and non-metals, such as $Sb$, $Te$, and $Po$.

s block

Includes groups $1A$ and $2A$ with electron configurations ending in the s subshell.

p block

Includes groups $3A$ through $8A$ with electron configurations ending in the p subshell.

d block

Contains the transition elements, categorized as Group B.

f block

Contains the inner transition elements, also known as rare earths ($\text{tierras raras}$).

Atomic Radius ($\text{Radio atómico}$)

A periodic property that decreases across a period from left to right and increases down a group.

Ionization Energy ($\text{Energía de ionización}$)

The energy required to remove an electron from an atom in kl/mol; it increases from left to right and from bottom to top.

Electronegativity ($\text{Electronegatividad}$)

The ability of an atom to attract electrons; it increases from left to right across a period and from bottom to top up a group.

Electron Affinity ($\text{Afinidad electrónica}$)

A property that increases from left to right across a period and from bottom to top up a group.

Fluorine ($F$)

The chemical element in the Halogen group that possesses the highest electronegativity.

Actinides

The series of elements that includes radioactive elements like Uranium ($U$).

Coulomb Force

The force of attraction inside an atom that keeps the particles together.

Hydrogen Bonds ($\text{Puentes de hidrógeno}$)

Intermolecular attraction forces that explain the high boiling points of covalent compounds like $HF$, $H_2O$, and $NH_3$.

Van der Waals Forces

Weak attractions that maintain molecules together.

Dipole

Occurs when a molecule momentarily acquires a partially positive charge and a partially negative charge.

Ionic Halides

Compounds formed by the reaction of metals with halogens.

Covalent Halides

Compounds formed by the reaction of non-metals with halogens.