Correct option is B
The correct answer is (b) increasing atomic number in the horizontal rows.
Explanation:
The Modern Periodic Table arranges elements based on their increasing atomic number (number of protons) across the horizontal rows (periods).
This arrangement was proposed by Mendeleev and later refined by Moseley, who discovered that atomic number, rather than atomic mass, is the more fundamental property for organizing elements.
Information booster
Modern Periodic Table:
- Periods represent elements with increasing atomic number and gradually changing properties.
- Groups contain elements with similar chemical properties due to the same number of valence electrons.
- The periodic table is divided into s-block, p-block, d-block, and f-block based on electron configurations.
- The Periodic Law states that properties of elements repeat periodically when arranged by atomic number.
- Moseley's discovery confirmed that elements should be arranged by atomic number, not atomic mass.
- Metals are found on the left, non-metals on the right, and metalloids between metals and non-metals.
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