The correct decreasing order for metallic character is :

Solution

Chemistry ma’am · 4 steps

Metallic character is how easily an atom gives away electrons, so find where each one sits in the table.

1. What it measures. Metallic character is the tendency to lose electrons and form positive ions. Low ionisation enthalpy and a large atom both make that easier.
2. The two trends. Across a period, from left to right, metallic character decreases because nuclear charge grows and atoms shrink. Down a group it increases because the outer electron sits farther from the nucleus.

   Element	Period, group	Nature
   Na	3, group 1	most metallic, loses 1 electron very easily
   Mg	3, group 2	metal, one place right of Na
   Be	2, group 2	metal, but small and less metallic than Mg (above it in group 2)
   Si	3, group 14	metalloid
   P	3, group 15	non-metal, least metallic

3. Place Be. Be sits above Mg, so it is less metallic than Mg. It is still a true metal, so it ranks above the metalloid Si and the non-metal P.
4. So. The decreasing order is Na > Mg > Be > Si > P, which is option (a).

The idea to keep. Metallic character rises as you go left and down the periodic table. Rank the metals first, then the metalloids, then the non-metals, and use the group trend to place elements from different periods.

Answer from the NTA final answer key. Solution by PrepWiser.