Periodicity Flashcards
Alkaline Earth Metals? Block?
Group 2: Beryllium (Be) Magnesium (Mg) Calcium (Ca) Strontium (Sr) Barium (Ba) Radium (Ra)
s-block.
Alkali Metals? Block?
Group 1: Lithium (Li) Sodium (Na) Potassium (K) Rubidium (Rb) Caesium (Cs) Francium (Fr)
s-block.
Transition Metals? Block?
d-block.
Noble gases? Block?
Group 0: Helium (He) Neon (Ne) Argon (Ar) Krypton (Kr) Xenon (Xe) Radon (Rn)
p-block.
Halogens? Block?
Group 7: Fluorine (F) Chlorine (Cl) Bromine (Br) Iodine (I) Astatine (At)
p-block.
Do d block elements (transition metals) tend to lose or gain electrons? Which electrons? s/p/d/f? Do they form positive or negative ions?
The d block elements tend to lose s and d electrons to form positive ions.
What makes Group 0 elements inert?
Full sub-shells.
Which groups of the Periodic Table tend to gain electrons to form negative ions?
Groups 5, 6 and 7.
In the s-block (metals) do elements become more or less reactive as you go down a group?
More reactive.
Are transition metals reactive?
No, they are unreactive.
What is a Group in the Periodic Table?
A group is a vertical column of elements.
What is a period in the Periodic Table?
Horizontal rows of elements.
Elements in Groups 1, 2 and 3 lose outer electrons to form what?
Ionic compounds.
Explain the meaning of the term First Ionisation Energy.
The energy required to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous positive ions.
Li and Mg are ______ block elements?
s.
Cl is a ________ block element?
p.
Co is a ________ block element?
d.
State and explain the general trend in first ionisation energies for the elements Na to P.
Trend: Increases
Explanation: The nuclear charge increases, shielding stays the same and there is a greater attraction for the electrons.
State which one of these elements from Na to P deviates from this general trend and explain why it occurs.
Element: Aluminium
Explanation: Electron is in 3p orbital (higher orbital) and therefore increased shielding makes the electron easier to remove. Less energy is required.
State which one of the elements from Na to P has the highest melting point and explain your answer.
Element: Silicon
Explanation: Silicon has a macromolecular structure therefore it has strong covalent bonds that require a lot of energy to break bonds.
State the type of structure shown by crystals of Sulphur and Phosphorus. Explain why the melting pointing of Sulphur is HIGHER than the MP of Phosphorus.
Type of Structure: Simple Molecular.
Sulphur is a bigger molecule than Phosphorus. Sulphur also contains more Van der Waals to be broken.
Explain why the melting point of Aluminium is higher than the melting point of Sodium.
Aluminium has a bigger charge than Sodium (Al = 3+, Na = 1+).
Al has more free delocalised electrons.
Aluminium has stronger metallic bonding.
Identify, from Period 2 elements Li to N, the element that has the largest atomic radius.
Lithium.
State the general trend in first ionisation energies for the Period 2 elements Lithium to Nitrogen.
Increases.
Identify the element that deviates from this general trend, from Li to N and explain your answer.
Element: Boron
Explanation: Electron is in 2p orbital (higher orbital) therefore the shielding increases and the electron becomes easier to remove.
State and explain the trend in atomic radius of the Period 3 elements from Sodium to Chlorine.
Trend: Decreases
Explanation: The nuclear charge increases, shielding stays the same and the attraction for the electrons becomes greater so atoms shrink.
State which of the first, second or third ionisations of Al would produce an ion with the electronic configuration 1s(2), 2s(2), 2p(6), 3s(1).
Second.
Explain why the value of the first ionisation energy of Sulphur is less than the value of the first ionisation of Phosphorus.
The pair of electrons in the 3p orbital repel each other and therefore less energy is required.
Write an equation to show the process that occurs when the first ionisation energy of Al is measured.
Al(g) > Al+(g) + e-
Identify the element in Period 2 that has the highest first ionisation energy and give its electron configuration.
Element: Neon
Electron Configuration: 1s(2), 2s(2), 2p(6)
State the trend in the first ionisation energies in Group 2 from Be to Ba. Explain your answer in terms of a suitable model of atomic structure.
Trend: Decreases
Explanation: As you go down a group there is increased shielding, a greater distance from the nucleus and so the outer electrons become easier to remove.
Explain why the second ionisation energy of Carbon is higher than the first ionisation energy of Carbon.
An electron is being removed from a positive ion (closer to the nucleus).
Deduce the element in Period 2, from Li to Ne, that has the highest second ionisation energy.
Lithium.
