In the modern periodic table, the element with atomic number 117 belongs to:
A. Group 1, Period 7
B. Group 18, Period 6
C. Group 17, Period 6
D. Group 17, Period 7
Answer: Option D
Solution (By JKExamLibrary)
Element 117 (tennessine, Ts) is a halogen in Group 17, Period 7. The modern periodic table has 7 periods and 18 groups. Halogens are in Group 17. Period 7 starts with Fr (87) and ends with Og (118). Ts is two places before Og. Exam trick: For atomic numbers after 86 (Rn), use period 7. Group 17 elements are F, Cl, Br, I, At, Ts.
Consider the following statements: 1. Lattice energy increases with an increase in the charge of the ions. 2. Lattice energy decreases with an increase in the size of the ions. Which is/are correct?
Explanation:
Lattice energy is the energy required to separate one mole of an ionic solid into its gaseous ions. According to Coulomb's law, it is directly proportional to the product of the ionic charges and inversely proportional to the sum of their radii. Thus, higher charges and smaller sizes both increase lattice energy.
Explanation:
Acid rain results from SO₂ and NOₓ (oxides of nitrogen) dissolving in water vapor to form sulfuric and nitric acids. These are released from burning fossil fuels and industrial processes. Carbon dioxide forms weak carbonic acid (normal rain pH ~5.6), but SO₂ and NOₓ cause pH below 5.0.
Explanation:
Water decomposes as 2H₂O → 2H₂ + O₂. So 2 volumes of H₂ for every 1 volume of O₂, ratio 2:1. Hydrogen collected at cathode, oxygen at anode.
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