Module 2 NTK definitions

Question 1

What are isotopes?

Answer 1

Atoms of the same element (same number of protons and electrons) with different numbers of neutrons and different masses

Question 2

What is relative isotopic mass?

Answer 2

The mass of an atom of an isotope compared with 1/12 of the mass of an atom of carbon-12

Question 3

What is relative atomic mass?

Answer 3

The weighted mean mass of an atom of an element compared with 1/12 of the mass of an atom of carbon-12

Question 4

What is an atomic orbital?

Answer 4

A region around the nucleus that can hold up to two electrons, with opposite spins

Question 5

What does the term ‘anhydrous’ imply?

Answer 5

When all the waters of crystallisation have been removed from a compound

Question 6

What does the term ‘hydrated’ imply?

Answer 6

When water of crystallisation is present in a crystal compound

Question 7

What is water of crystallisation?

Answer 7

The water present in a compound giving the compound a crystalline appearance

Question 8

What is percentage (%) yield?

Answer 8

Actual mass of product/Theoretical mass of product * 100

Question 9

What is atom economy?

Answer 9

Molecular mass of desired product/Molecular mass of ALL product * 100

Question 10

What is an acid?

Answer 10

Proton (H+) donor

Question 11

What is a base?

Answer 11

Proton (H+) acceptor

Question 12

What is an alkali?

Answer 12

A soluble base that dissolves in water to release OH- ions in aqueous solution

Question 13

What is oxidation?

Answer 13

The loss of electrons/increase in oxidation number (state)

Question 14

What is reduction?

Answer 14

The gain of electrons/decrease in oxidation number (state)

Question 15

What is an oxidising agent?

Answer 15

A reagent which oxidises another species (and is reduces itself) by gaining electrons

Question 16

What is a reducing agent?

Answer 16

A reagent which reduces another species (and is oxidised itself) by losing electrons

Question 17

What is a redox reaction?

Answer 17

A reaction where both oxidation and reduction takes place

Question 18

What is disproportionation?

Answer 18

A reaction in which the same element is both oxidised and reduced

Question 19

What is a metallic bond?

Answer 19

Strong electrostatic attraction between positively charged ions (cations) and delocalised electrons

Question 20

What is an ionic bond?

Answer 20

Strong electrostatic attraction between positive and negatively charged ions

Question 21

What is a covalent bond?

Answer 21

Electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms

Question 22

What is a dative (co-ordinate) covalent bond?

Answer 22

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

Question 23

What is electronegativity?

Answer 23

The ability of an atom to attract the bonding electrons towards itself in a covalent bond