Module 2 NTK definitions Flashcards
What are isotopes?
Atoms of the same element (same number of protons and electrons) with different numbers of neutrons and different masses
What is relative isotopic mass?
The mass of an atom of an isotope compared with 1/12 of the mass of an atom of carbon-12
What is relative atomic mass?
The weighted mean mass of an atom of an element compared with 1/12 of the mass of an atom of carbon-12
What is an atomic orbital?
A region around the nucleus that can hold up to two electrons, with opposite spins
What does the term ‘anhydrous’ imply?
When all the waters of crystallisation have been removed from a compound
What does the term ‘hydrated’ imply?
When water of crystallisation is present in a crystal compound
What is water of crystallisation?
The water present in a compound giving the compound a crystalline appearance
What is percentage (%) yield?
Actual mass of product/Theoretical mass of product * 100
What is atom economy?
Molecular mass of desired product/Molecular mass of ALL product * 100
What is an acid?
Proton (H+) donor
What is a base?
Proton (H+) acceptor
What is an alkali?
A soluble base that dissolves in water to release OH- ions in aqueous solution
What is oxidation?
The loss of electrons/increase in oxidation number (state)
What is reduction?
The gain of electrons/decrease in oxidation number (state)
What is an oxidising agent?
A reagent which oxidises another species (and is reduces itself) by gaining electrons
What is a reducing agent?
A reagent which reduces another species (and is oxidised itself) by losing electrons
What is a redox reaction?
A reaction where both oxidation and reduction takes place
What is disproportionation?
A reaction in which the same element is both oxidised and reduced
What is a metallic bond?
Strong electrostatic attraction between positively charged ions (cations) and delocalised electrons
What is an ionic bond?
Strong electrostatic attraction between positive and negatively charged ions
What is a covalent bond?
Electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms
What is a dative (co-ordinate) covalent bond?
The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms, where only one of the atoms supplies both of the electrons shared
What is electronegativity?
The ability of an atom to attract the bonding electrons towards itself in a covalent bond
