Topic 3 Periodicity Flashcards
(21 cards)
What are alkali metals?
Group 1 elements. Strength of metallic bond gets weaker as atoms get larger.
What is an anion?
A negative (–) charged ion. Decrease in size across a period as they are isoelectronic but have an increased nuclear charge.
How does atomic radius change across a period?
Decreases across period as nuclear charge increases.
What is a catalyst?
A substance that increases the rate of reaction while being recoverable in the end stage of the reaction, unchanged.
Give an example of a catalytic transition metal used in the Haber process.
Fe
What is a cation?
A positive (+) charged ion. Decrease in size across a period.
What type of structure do chlorides of Na and Mg have?
Ionic structure.
What is the coordination number?
Number of lone pairs bonded to the metal ion.
What happens during a D-d transition?
The excitation of an e- from the lower of two energy level groups to the upper.
Define electronegativity.
Relative measure of the attraction that an atom has for a shared pair of e- when it is covalently bonded to another atom.
What are halide ions?
Ions of the halogens.
How can the presence of halide ions be detected?
By the addition of silver nitrate.
What is the definition of isoelectronic?
Containing the same number of e-.
What is a ligand?
A species which contains a non-bonding pair of electrons, able to form coordinate/dative covalent bonds.
What does melting point depend on?
Both the structure of element and type of attractive forces holding the atoms together.
What is a metalloid?
An element that possesses some of the properties of a metal and some of a non-metal.
What type of structure do metal oxides typically have?
Ionic.
What is periodicity?
The repeating pattern of physical and chemical properties as shown by the different periods.
What are the characteristics of a giant covalent structure?
Very hard but brittle, very high m.p. and b.p., do not conduct in any state, insoluble.
What is a transition element?
An element that possesses an incomplete d sub-level in one or more of its oxidation states.
Fill in the blank: The highest melting point of a period lies with _______.
[macromolecular covalent structure]
