Periodic Classification of Elements

These flashcards cover key concepts from the periodic classification of elements as discussed in the lecture, providing descriptions and definitions essential for understanding the periodic table and associated properties.

Periodic Table

A table that organizes elements by increasing atomic number, showing periodic trends in their properties.

Groups

Vertical columns in the periodic table where elements have similar chemical properties.

Periods

Horizontal rows in the periodic table, each representing a different energy level of electrons.

Periodic Law

The observation that the properties of elements are periodic functions of their atomic numbers.

Al-Razi

An early scientist who classified elements based on their physical and chemical properties.

Dobereiner's Triads

A classification system where groups of three elements with similar properties were identified, proposed by Johann Wolfgang Döbereiner.

Law of Octaves

A principle by Newlands stating that every eighth element exhibited similar properties when elements were arranged by increasing atomic mass.

Mendeleev

A Russian chemist who created the first periodic table, arranging elements by atomic mass and properties.

Atomic Number

The number of protons in the nucleus of an atom, which determines an element's identity.

s-block Elements

Elements in groups IA and IIA where the outermost electron is in an s orbital.

d-block Elements

Transition metals where the outermost electrons are in d orbitals.

p-block Elements

Elements in groups IIIA to VIIIA where the outermost electrons are in p orbitals.

Metalloids

Elements that have properties of both metals and non-metals.

Ionization Energy

The minimum energy required to remove an electron from an isolated atom in its gaseous state.

Electron Affinity

The amount of energy released or absorbed when an electron is added to a neutral atom to form a negative ion.

Hydration Energy

The energy released or absorbed when one mole of gaseous ions dissolves in water to form an infinitely dilute solution.

Halides

Binary compounds formed between halogens and other elements.

Hydrides

Binary compounds formed between hydrogen and other elements.

Oxidation State

The apparent charge of an atom in a compound; indicates the number of electrons gained or lost.

Amphoteric Oxides

Oxides that can act as either acids or bases depending on the nature of the other reactants.

Noble Gases

Elements in group VIIIA that are characterized by their lack of reactivity due to having a complete valence shell.

Lanthanides

A series of 14 elements from atomic numbers 58 to 71, known for their similar properties.

Actinides

A series of 14 elements from atomic numbers 90 to 103, many of which are radioactive.

Bonds in Covalent Hydrides

Generally non-conductive substances formed by elements with high electronegativity and involve shared electrons.

Alkali Metals

Elements of group IA, known for their strong reactivity with water and tendency to form hydroxides.

Alkaline Earth Metals

Elements of group IIA, characterized by their reactive, metallic properties but less so than alkali metals.