Periodic Table And Trends

Question 1

Atomic Radius

Answer 1

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

Question 2

First Ionisation Energy

Answer 2

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

Question 3

Second Ionization Energy

Answer 3

The energy required to remove an electron from an ion with one positive charge in the gaseous state i.e the energy required to carry out the following: x+ —>X2 + e-

Question 4

Electronegativity

Answer 4

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

Question 5

Element

Answer 5

A substance that cannot be split into a simpler substance by chemical means

Question 6

Triad

Answer 6

Is a group of three elements with similar chemical properties in which the atomic weight of the middle element is approximately equal to the average of the other two

Question 7

Newland’s octaves

Answer 7

Group of elements arranged in order of increasing atomic weight in which the first and the eighth element of each group have similar properties

Question 8

Mendeleev’s Periodic Law

Answer 8

When elements are arranged in order of increasing atomic weight the properties of the elements recur periodically

Question 9

Atomic Number

Answer 9

The number of protons in the nucleus of that atom

Question 10

Modern Periodic table

Answer 10

Arrangement of elements in order of increasing atomic number

Question 11

Modern Periodic Law

Answer 11

When elements are arranged in order of increasing atomic number, the properties of the elements recur periodically

Question 12

Mass number

Answer 12

The sum of the number of protons and neutrons in the nucleus of an atom of that element

Question 13

Isotopes

Answer 13

Atoms of the same element that have different mass numbers due to the different number of neutrons in the nucleus

Question 14

Relative Atomic Mass

Answer 14

The average of the mass numbers of the isotopes of the element, as they occur naturally, taking their abundances into account and expressed on a scale in which the atoms of the carbon-12 isotope have a mass of exactly 12 units

Question 15

Principle of Mass Spectrometry

Answer 15

Charged particles moving in a magnetic field are deflected to different extents according to their masses and are thus separated according to their masses

Question 16

Electron Configuration

Answer 16

The arrangement of electrons in an atom of that element

Question 17

Aufbau principle

Answer 17

When building up the electron configuration of an atom in its ground state the electrons occupy the lowest available energy level

Question 18

Hund’s Rule of Maximum Multiplicity

Answer 18

When two or more orbitals of equal energy are available, the electrons occupy them singly before filling them in pairs

Question 19

Pauli Exclusion Principle

Answer 19

No more than two electrons may occupy an orbital and they must have opposite spin

Question 20

Bond Energy

Answer 20

The average energy required to break a bond and to separate the atoms in the gaseous state