Lecture 3 -the Periodic Table Flashcards
What is the aim of Topic 3 – The Periodic Table?
Revise nomenclature and chemical calculations, understand trends and groups of elements, determine electron configurations, and calculate electrons in ions.
Elements in the periodic table are arranged in order of increasing _______.
[atomic number]
What are the vertical columns in the periodic table called?
[groups]
What are the horizontal rows in the periodic table called?
[periods]
Elements in the same group have _______ chemical properties.
[similar]
What is the atomic radius?
The total distance from the nucleus of an atom to the outermost orbital of its electron.
What is the trend of atomic radius within a group on the periodic table?
Atomic radius increases from top to bottom.
What causes the atomic radius to increase when moving down a group?
The increase in the principal energy number (n) of the outer electrons.
What is the trend of atomic radius within a period on the periodic table?
Atomic radius decreases from left to right.
What is effective nuclear charge (Z_eff)?
The net positive charge attracting an electron in an atom.
How is effective nuclear charge approximated?
Z_eff = Z - S, where Z is the atomic number and S is the number of shielding electrons.
What is electronegativity?
The measure of the ability of an atom in a chemical compound to attract electrons from another compound.
Which element is the most electronegative?
Fluorine (F) with a value of 4.0.
What is the trend in electronegativity within a period?
Electronegativity increases from left to right.
What is the trend in electronegativity down a group?
Electronegativity decreases from top to bottom.
What is bond polarity?
The concept that describes the sharing of electrons between atoms.
In a non-polar covalent bond, how are electrons shared?
Electrons are shared equally between two atoms.
What is the octet rule?
Stability comes from having a full outer shell of electrons, typically eight.
What are alkali metals?
Group 1 elements that have one electron in the outermost shell.
What is the electron configuration of Lithium (Li)?
1s² 2s¹
What happens to the atomic radius when forming cations?
The radius decreases because there is one less shell of electrons.
Which group of elements is known as alkaline earth metals?
[Group 2]
What is the general trend for ionic radii in groups?
Atomic and ionic radii increase as you go down the group.
What are transition metals known for?
High melting points and the ability to exist in a range of oxidation states.
What is the electron configuration notation for Magnesium (Mg)?
[Ne] 3s²
What principle states that electrons will occupy the lowest energy orbitals first?
[Aufbau principle]
What is Hund’s rule?
No two electrons with the same spin can occupy the same orbital.
What is the maximum number of electrons per orbital?
Two electrons.
What does the Pauli exclusion principle state?
No two electrons in an atom can have the same set of quantum numbers.
What is the electron configuration of Neon (Ne)?
1s² 2s² 2p⁶
Which group forms M³⁺ ions?
[Group 13 (III)]
What are the elements in Group 15 known as?
[Pnictogens]
What type of bond forms when the difference in electronegativity is large enough?
[Ionic bond]
What is the electron configuration of Arsenic (As)?
[Ar] 4s² 3d¹⁰ 4p³
What is the primary characteristic of metalloids?
Having properties intermediate between metals and non-metals.
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 electron configuration for Zinc?
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s²
What is ionisation energy?
Minimum energy required to remove an electron from the ground state of an isolated gaseous atom or ion.
What is the first ionisation energy (I₁)?
Energy required to remove one electron from a gaseous neutral atom.
What is the second ionisation energy (I₂)?
Energy required to remove a second electron from a cation.
True or False: The greater the ionisation energy, the easier it is to remove an electron.
False
What are positive ions called?
Cations
What are negative ions called?
Anions
What is the symbol for Sodium in its neutral state?
Na
What is the ion form of Magnesium?
Mg²⁺
What is the ion form of Oxygen?
O²⁻
Fill in the blank: Ions can gain or lose up to ______ electrons.
3
Which group of elements loses one electron to become +1 ions?
Group One
Which group of elements loses two electrons to become +2 ions?
Group Two
What type of ions do Transition Metals typically form?
+1, +2, or +3
What do Group Five (15) elements do to become ions?
Gain three electrons
What do Group Six (16) elements do to become ions?
Gain two electrons
What do Group Seven (17) elements do to become ions?
Gain one electron
What do Noble Gases (Group Eight) do in terms of ion formation?
Do not gain or lose electrons
Calculate the electron loss/gain of Lithium: ______
+1
Calculate the electron loss/gain of Nitrogen: ______
-3
Calculate the electron loss/gain of Argon: ______
0
Calculate the electron loss/gain of Magnesium: ______
+2
Calculate the electron loss/gain of Gallium: ______
+3
Give an example of an ionic compound formed between Group One and the halogens.
NaCl (Sodium Chloride)
Give an example of an ionic compound formed between Group Two and a Group 16 element.
CaO (Calcium Oxide)
Give an example of an ionic compound formed between the transition metal ion Fe³⁺ and a Group 17 element.
FeCl₃ (Iron(III) Chloride)
