Ch4: The Periodic Table

Question 1

Element

Answer 1

substance that cannot be split into simpler substances by chemical means

Question 2

Triad

Answer 2

Group of three elements with similar chemical properties in which the atomic weight (relative atomic mass) of the middle element is approximately equal to the average of the other two

Question 3

Newland’s Octaves

Answer 3

Arrangements of elements in which the first and eighth element, counting from a particular element, have similar properties

Question 4

Mendeleev’s Periodic Law

Answer 4

When elements are arranged in order of increasing atomic weight (relative atomic mass), the properties of the elements recur periodically
i.e. the properties displayed by an element are repeated at regular intervals in other elements

Question 5

Atomic number

Answer 5

the number of protons in the nucleus of that atom

Question 6

Modern Periodic Table

Answer 6

an arrangement of elements in order of increasing atomic number

Question 7

Modern Periodic Law

Answer 7

When elements are arranged in order of increasing atomic number, the properties of the the elements recur periodically
i.e. the properties displayed by an element are repeated at regular intervals in other elements

Question 8

Mass number

Answer 8

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

Question 9

Isotopes

Answer 9

Atoms of the same element (i.e. they have the same atomic number) which have different mass numbers due to the different number of neutrons in the nucleus

Question 10

Relative atomic mass

Answer 10

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

Question 11

Principle of mass spectrometry

Answer 11

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

Question 12

Electron configuration

Answer 12

shows the arrangement of electrons in an atom of an element

Question 13

Aufbau Principle

Answer 13

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

Question 14

Hund’s Rule of Multiplicity

Answer 14

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

Question 15

Pauli Exclusion Principle

Answer 15

states that no more than two electrons may occupy an orbital and they must have opposite spin