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  1. Problems
  2. /The Periodic Table

The Periodic Table

Chemistry
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52 problems
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1.
On the Pauling scale sodium is 0.9, hydrogen 2.1, carbon 2.5 and chlorine 3.0. New
High School (11–12) · Periodic Trends, Groups and FamiliesStemPy LabStemPy Lab
Hard
2.
Sodium oxide, aluminium oxide and sulphur trioxide are each tested with water, with dilute acid and… New
High School (11–12) · Periodic Trends, Groups and FamiliesStemPy LabStemPy Lab
Medium
3.
Use the valences of the groups to write three formulas. New
High School (11–12) · Periodic Trends, Groups and FamiliesStemPy LabStemPy Lab
Easy
4.
The electron gain enthalpy of chlorine is -349 kJ mol⁻¹ and that of fluorine -328 kJ mol⁻¹. New
High School (11–12) · Periodic TrendsStemPy LabStemPy Lab
Hard
5.
The first ionisation enthalpy of nitrogen is 1402 kJ mol⁻¹ and that of oxygen is 1314 kJ mol⁻¹… New
High School (11–12) · Periodic TrendsStemPy LabStemPy Lab
Medium
6.
The first four ionisation enthalpies of an element are 578, 1817, 2745 and 11577 kJ mol⁻¹. New
High School (11–12) · Periodic TrendsStemPy LabStemPy Lab
Medium
7.
A sodium street lamp holds sodium vapour. New
High School (11–12) · Periodic TrendsStemPy LabStemPy Lab
Easy
8.
Suppose only the two 1s electrons shield the outer electrons of period 2, so S = 2. New
High School (11–12) · Periodic TrendsStemPy LabStemPy Lab
Hard
9.
The atomic radius of sodium is 186 pm. Potassium, below it in group 1, is 231 pm. New
High School (11–12) · Periodic TrendsStemPy LabStemPy Lab
Medium
10.
The ions S²⁻, Cl⁻, K⁺ and Ca²⁺ all have the same number of electrons. New
High School (11–12) · Periodic TrendsStemPy LabStemPy Lab
Medium
11.
The two nuclei in a bromine molecule, Br₂, are 228 pm apart. New
High School (11–12) · Periodic TrendsStemPy LabStemPy Lab
Easy
12.
An element of period 4 has the outer configuration 3d⁵ 4s². New
High School (11–12) · Development of the Periodic Table, Groups and FamiliesStemPy LabStemPy Lab
Medium
13.
A lanthanoid has the configuration [Xe] 4f⁷ 6s². New
High School (11–12) · Development of the Periodic Table, Groups and FamiliesStemPy LabStemPy Lab
Hard
14.
An element sits in period 5 and group 14. Write its outer configuration and find its atomic number. New
High School (11–12) · Development of the Periodic Table, Groups and FamiliesStemPy LabStemPy Lab
Medium
15.
Arsenic has Z = 33. Write its configuration with a noble gas core, and find its period, group and… New
High School (11–12) · Development of the Periodic Table, Groups and FamiliesStemPy LabStemPy Lab
Easy
16.
Period 6 begins with the filling of the 6s subshell. New
High School (11–12) · Development of the Periodic TableStemPy LabStemPy Lab
Medium
17.
Give the temporary IUPAC name and symbol of the elements with Z = 106, 109 and 120. New
High School (11–12) · Development of the Periodic TableStemPy LabStemPy Lab
Easy
18.
Three metals give these values of √(ν) for their strongest X-ray line: calcium (Z = 20), 9.46 ×… New
High School (11–12) · Development of the Periodic TableStemPy LabStemPy Lab
Medium
19.
Tellurium (127.6 u) is heavier than iodine (126.9 u). New
High School (11–12) · Development of the Periodic TableStemPy LabStemPy Lab
Hard
20.
Newlands' list, in order of atomic mass, began: H, Li, Be, B, C, N, O, F, Na, Mg, Al, Si, P, S, Cl… New
High School (11–12) · Development of the Periodic TableStemPy LabStemPy Lab
Medium
21.
In Mendeleev's table the gap for eka-silicon had silicon (28.09 u) above, tin (118.71 u) below… New
High School (11–12) · Development of the Periodic TableStemPy LabStemPy Lab
Medium
22.
Calcium (40.08 u), strontium (87.62 u) and barium (137.33 u) behave alike. New
High School (11–12) · Development of the Periodic TableStemPy LabStemPy Lab
Easy
23.
Hydrogen is placed at the top of group 1, but it is hard to place.
High School (9–10), General · Groups and FamiliesStemPy LabStemPy Lab
Medium
24.
An element has the electron arrangement 2, 8, 18, 7.
High School (9–10), General · Groups and FamiliesStemPy LabStemPy Lab
Medium
25.
The melting points of lithium and potassium are 454 K and 337 K.
High School (9–10), General · Groups and FamiliesStemPy LabStemPy Lab
Medium
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