Chapter 5,11, 24: Chem Definitions

Question 1

Octet Rule

Answer 1

When bonding occurs, atoms tend to reach an arrangement with 8 electrons in the outermost energy level

Question 2

Ion

Answer 2

A charged atom or group of atoms

Question 3

Compound

Answer 3

2 or more different elements chemically combined

Question 4

Ionic bond

Answer 4

The force of attraction between oppositely charged ions in a compound through the transfer of electrons from one atom to another

Question 5

Transition metal

Answer 5

One that forms at least one ion with a partially filled d sublevel

Question 6

Molecule

Answer 6

A group of atoms joined together

Question 7

Valency

Answer 7

The number of atoms of hydrogen or any other monovalent element with which each atom of the element combines

Question 8

Sigma bond

Answer 8

The head-on overlap of 2 orbitals

Question 9

Pi bond

Answer 9

The sideways overlap of p orbitals

Question 10

Electronegative

Answer 10

The relative attraction than an atom in a molecule has for the shared pair of electrons in a covalent bond

Question 11

Polar covalent bond

Answer 11

A bond with which there is unequal sharing of electrons

eg, HCl

Question 12

1.8 or more

Answer 12

Ionic bond

Question 13

1.7 or less

Answer 13

Covalent bond

Question 14

0.5 - 1.6

Answer 14

Polar covalent bond

Question 15

0.4 or less

Answer 15

Non-polar

Question 16

Intramolecular bonding

Answer 16

Bonding that takes place within a molecule

e.g, polar covalent bonding

Question 17

Intermolecular bonding

Answer 17

Forces of attraction that exists between molecules

e.g, Van der Waals forces

Question 18

Van der Waals forces

Answer 18

Weak attractive forces between molecules resulting from the formation of temporary dipoles

Question 19

Dipole-dipole forces

Answer 19

Forces of attraction between the negative pole of one polar molecule and the positive pole of another polar ,molecule

Question 20

Hydrogen bonds

Answer 20

Particular types of dipole-dipole attractions between molecules in which hydrogen atoms are bounded to nitrogen, oxygen or fluorine

Question 21

Atomic radius

Answer 21

Half the distance between the nuclei of two atoms of the same element that are joined together by covalent bonds

Question 22

First ionisation of energy

Answer 22

The minimum energy required to completely remove the most loosely bound electron from a neutral gaseous atom in its ground state

Question 23

Formula for first ionisation of energy

Answer 23

X(g) —> X+(g) + e-

Question 24

Second ionisation of energy

Answer 24

The energy required to remove an electron from an ion with one positive charge in the gaseous state

Question 25

Formula for second ionisation of energy

Answer 25

X+(g) —> X2+(g) + e-

Question 26

One mole

Answer 26

The amount of a substance that contains 6 X 10^23 particles of that substance

Question 27

Relative molecular mass

Answer 27

The average mass of one molecule of a compound compared with 1/12 of the mass of the atom of the carbon-12 isotope

Question 28

Molecular formula

Answer 28

A compound which shows the number and type of each atom present in a molecule of that compound

Question 29

Empirical formula

Answer 29

The formula showing the simplest whole number ration of the number of different atoms present in the molecule