Modern periodic table by Mosley states that

Options

A. properties of element are periodic function of Atomic mass
B. properties of element depend upon number of neutrons
C. properties of element depend upon number of reaction
D. properties of elements are periodic function of atomic number

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Modern Periodic Table**: The modern periodic table, developed by Moseley, organizes elements based on their atomic number rather than atomic mass. This was a significant advancement in the classification of elements.

2. **Structure of the Periodic Table**: The periodic table consists of 18 groups (vertical columns) and 7 periods (horizontal rows). Each group contains elements that share similar chemical properties.

3. **Atomic Number as the Basis**: Moseley proposed that the elements should be arranged in order of increasing atomic number. This means that the elements are placed in the table based on the number of protons in their nucleus.

4. **Example of Element Placement**: For instance, hydrogen (H) is in group 1 and period 1 with an atomic number of 1. Helium (He), which is in group 18 and period 1, has an atomic number of 2. Similarly, lithium (Li) in group 1 and period 2 has an atomic number of 3, and beryllium (Be) in group 2 and period 2 has an atomic number of 4.

5. **Periodic Properties**: The periodic properties of elements, such as reactivity, ionization energy, and electronegativity, are periodic functions of their atomic number. This means that as you move across a period or down a group, these properties exhibit a predictable pattern.

6. **Conclusion**: Therefore, Moseley’s statement regarding the modern periodic table is that the properties of the elements are periodic functions of their atomic number, not their atomic mass or other factors.

**Final Statement**: The modern periodic table, as proposed by Moseley, states that the properties of elements are periodic functions of their atomic number.

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