In the periodic table, the atomic number of iodine is 53. For which of the following elements is the atomic number greater than that of iodine?

Introduction / Context:
Questions comparing atomic numbers of different elements test your familiarity with the periodic table and the relative positions of common metals and non metals. Iodine is a well known halogen with atomic number 53. To answer this question, you need to know which among the listed elements lies beyond iodine in terms of atomic number, meaning it appears later in the periodic table sequence.

Given Data / Assumptions:

• Iodine (I) has atomic number 53.
• The elements given are silver (Ag), bromine (Br), platinum (Pt), and zinc (Zn).
• Atomic number increases as we move from left to right along a period and from top to bottom down a group.
• We assume the standard periodic table with elements ordered by increasing atomic number.

Concept / Approach:
Atomic number is equal to the number of protons in the nucleus of an atom. Elements appearing later in the periodic table have larger atomic numbers than those appearing earlier. To solve this problem, we recall or look up the approximate positions and atomic numbers of silver, bromine, platinum, and zinc. We then simply compare each value with 53 and select the element whose atomic number is greater than 53.

Step-by-Step Solution:
Step 1: Recall the atomic numbers of the options. Bromine (Br) has atomic number 35. Silver (Ag) has atomic number 47. Zinc (Zn) has atomic number 30. Platinum (Pt) has atomic number 78. Step 2: Compare each with iodine's atomic number 53. 35 (Br) < 53, so bromine is smaller than iodine. 47 (Ag) < 53, so silver is smaller than iodine. 30 (Zn) < 53, so zinc is smaller than iodine. 78 (Pt) > 53, so platinum has a greater atomic number than iodine. Step 3: Conclude that platinum is the only element in the list with atomic number greater than 53.

Verification / Alternative check:
Looking at the periodic table, iodine is located in Period 5, Group 17. Platinum, however, lies far to the right and lower down, in Period 6, Group 10 among the transition metals. It is naturally expected that an element in Period 6 will have an atomic number significantly higher than 53. Quick reference charts or textbooks list platinum as element 78. This clear separation in position and atomic number confirms that platinum alone has a greater atomic number than iodine among the given options.

Why Other Options Are Wrong:
Option A (Silver): Atomic number 47, which is less than iodine's 53, so it cannot satisfy the condition. Option B (Bromine): Atomic number 35; bromine lies above iodine in Group 17 and therefore has a smaller atomic number. Option D (Zinc): Atomic number 30; zinc sits much earlier in the periodic table than iodine and clearly has fewer protons.

Common Pitfalls:
A common error is confusing atomic mass and atomic number, which can lead students to think heavier elements in terms of mass must always appear later in the table. Another mistake is misremembering the exact atomic numbers of common transition metals like silver and platinum. To avoid these issues, remember that atomic number strictly counts protons, and periodic table order is based on atomic number, not mass. For quick recall, it helps to know approximate positions: iodine at 53 and platinum around the heavy transition metals at 78.

Final Answer:
The element whose atomic number is greater than that of iodine is Platinum.