Module 2- Foundations in chemistry

Question 1

Isotopes

Answer 1

Isotopes are atoms of same element with the same number of protons, but different numbers of neutrons.

Question 2

Mass Number

Answer 2

The total number of protons and neutrons in the atom

Question 3

Atomic number

Answer 3

The number of protons in the nucleus

Question 4

Relative isotopic mass

Answer 4

The mass of one isotope compared to one twelfth of the mass of one atom of carbon-12

Question 5

Relative atomic mass

Answer 5

The weighted mean mass of one atom compared to one twelfth of the mass of one atom of carbon-12

Question 6

Relative molecular mass

Answer 6

The average mass of a molecule compared to one twelfth of the mass of one atom of carbon-12

Question 7

Mole

Answer 7

The amount of substance in grams that has the same number of particles as there are atoms in 12 grams of carbon-12

Question 8

Molar mass

Answer 8

The mass in grams of 1 mole of a substance and is given the unit of g mol-1

Question 9

Molar gas volume

Answer 9

The volume of 1 mole of a gas at a given temperature and pressure

Question 10

Empirical formula

Answer 10

The simplest ratio of atoms of each element in the compound

Question 11

Molecular formula

Answer 11

The actual number of atoms of each element in the compound

Question 12

Solution

Answer 12

A mixture formed when a solute dissolves in a solvent

Question 13

Average bond enthalpy

Answer 13

A measurement for covalent bond strength

Question 14

Dative covalent bond

Answer 14

Forms when the shared pair of electrons in the covalent bond come from only one of the bonding atoms.

Question 15

Covalent bond

Answer 15

The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms

Question 16

Ionic bond

Answer 16

The electrostatic force of attraction between oppositely charged ions formed by electron transfer.

Question 17

Electronegativity

Answer 17

Electronegativity is the relative tendency of an atom in a covalent bond in a molecule to attract electrons in a covalent bond to itself.

Question 18

First ionization energy

Answer 18

The energy required when one mole of gaseous atoms forms one mole of gaseous ions with a single positive charge

Question 19

Second ionization energy

Answer 19

The energy required when one mole of gaseous ions with a single positive charge forms one mole of gaseous ions with a double positive charge

Question 20

Metallic bonding

Answer 20

The electrostatic force of attraction between the positive metal ions and the delocalised electrons