Topic 3 The Periodic Table Flashcards
What is the aim of studying the periodic table?
To revise nomenclature, chemical calculations, trends in the periodic table, groups of elements, determine electron configurations, and calculate electrons in ions.
What are the columns of the periodic table called?
Groups.
What are the horizontal rows of the periodic table called?
Periods.
What is the atomic radius?
The total distance from the nucleus of an atom to the outermost orbital of its electron.
What trend occurs in atomic radius within a group as you move from top to bottom?
Atomic radius increases.
What causes the increase in atomic radius down a group?
Increase in the principal energy number (n) of the outer electrons.
What trend occurs in atomic radius within a period as you move from left to right?
Atomic radius decreases.
What is the effective nuclear charge (Zeff)?
The net positive charge attracting an electron in an atom.
How is effective nuclear charge approximated?
Zeff = Z – S, where Z is atomic number and S is the number of shielding electrons.
What is electronegativity?
The measure of an atom’s ability to attract electrons in a chemical compound.
Which element is the most electronegative?
Fluorine (F).
What trend occurs in electronegativity within a period as you move from left to right?
Electronegativity increases.
What trend occurs in electronegativity down a group?
Electronegativity decreases.
What is the octet rule?
Stability comes from having a full outer shell of electrons, typically eight.
What are alkali metals?
Group 1 elements with one electron in the outermost shell.
What is the electron configuration of Lithium (Li)?
1s² 2s¹.
What is the electron configuration of Cesium (Cs)?
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s¹.
What are alkaline earth metals?
Group 2 elements with two electrons in their outer valence shell.
What is the typical oxidation state of transition metals?
They can exist in a range of oxidation states from +1 to +7.
What are the elements in Group 15 called?
Pnictogens.
What are the elements in Group 16 called?
Chalcogens.
What are the elements in Group 17 called?
Halogens.
What is the ability of an atom to withdraw a shared pair of electrons called?
Electropositivity.
Does Mg or Mg²⁺ have a smaller radius?
Mg²⁺.
What is the Aufbau principle?
Electrons occupy the lowest energy orbitals wherever possible.
What is the Pauli exclusion principle?
No two electrons with the same spin can occupy the same orbital.
What is Hund’s rule?
Electrons will occupy degenerate orbitals singly before pairing up.
What is the electron configuration notation for Magnesium?
[Ne] 3s².
What is a semiconductor?
Materials like silicon and germanium that partially conduct and partially insulate.
What is the electron configuration for Neon?
1s² 2s² 2p⁶
What is the electron configuration for Fluorine?
1s² 2s² 2p⁵
What is the electron configuration for Beryllium?
1s² 2s²
What is the electron configuration for Sodium?
1s² 2s² 2p⁶ 3s¹
What is the challenge electron configuration for Zinc?
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰
What is ionisation energy?
The minimum energy required to remove an electron from the ground state of the isolated gaseous atom or ion.
What is the first ionisation energy (I₁)?
The energy required to remove one electron from a gaseous neutral atom.
What is the second ionisation energy (I₂)?
The energy required to remove a second electron from a gaseous ion.
True or False: The greater the magnitude of ionisation energy, the easier it is to remove the electron.
False
Define a cation.
A positive ion that results from losing electrons.
Define an anion.
A negative ion that results from gaining electrons.
What is the ion symbol for sodium as a cation?
Na⁺
What is the ion symbol for magnesium as a cation?
Mg²⁺
What is the ion symbol for oxygen as an anion?
O²⁻
What is the ion symbol for chlorine as an anion?
Cl⁻
Fill in the blank: Ions can exist as _______ if they lose electrons.
+1, +2, or +3
Fill in the blank: Ions can exist as _______ if they gain electrons.
-1, -2, or -3
What do Group One elements do to form ions?
Lose one electron to become +1.
What do Group Two elements do to form ions?
Lose two electrons to become +2.
What do Transition Metals typically do to form ions?
Can vary but can be either +1, +2, or +3.
What do Group Three (13) elements do to form ions?
Lose three electrons to become +3.
What do Group Five (15) elements do to form ions?
Gain three electrons.
What do Group Six (16) elements do to form ions?
Gain two electrons.
What do Group Seven (17) elements do to form ions?
Gain one electron.
Fill in the blank: Group Eight (18) elements are _______ and do not gain or lose electrons.
stable
Challenge: What is an example of an ionic compound formed between Group One and the halogens?
NaCl (sodium chloride)
Challenge: Provide an example of an ionic compound formed between Group Two and a Group 16 element.
CaO (calcium oxide)
Challenge: Give an example of an ionic compound formed between Fe³⁺ and a Group 17 element.
FeCl₃ (iron(III) chloride)
