Question

Which of the following with respect to the Modern Periodic Table is NOT correct?

• A. It has 18 groups and 7 periods.
• B. The number of shells increases as we go down the group.
• C. The elements present in the same group have same number of valence electrons.
• D. Na, Mg and S belongs to the 4th period of the Modern Periodic Table

Answer 1

Answer:

D. Na, Mg and S belongs to the 4th period of the Modern Periodic Table

• Sodium (Na), Magnesium (Mg), and Sulfur (S) are elements that belong to the 3rd period, not the 4th period, of the Modern Periodic Table.

• The third period contains eight elements: sodium, magnesium, aluminium, silicon, phosphorus, sulfur, chlorine and argon.

• The first two, sodium and magnesium, are members of the s-block of the periodic table, while the others are members of the p-block.