Question

question 5 (2 points)
which of the following atoms has the largest first ionization energy?
si
na
k
mg
al

Explanation:

Ionization energy is the energy required to remove an electron from an atom. In the periodic table, ionization energy generally increases across a period (from left to right) and decreases down a group. Among the given elements, Na, Mg, Al, and Si are in the same period (period 3), and K is in period 4 (lower period, so lower ionization energy than period 3 elements). Among Na, Mg, Al, Si: Na has the lowest ionization energy as it is on the far left. Mg has a higher ionization energy than Na (due to filled 3s² configuration). Al has a lower ionization energy than Mg (as electron is removed from 3p which is higher in energy than 3s). Si has a higher ionization energy than Al as we move right in the period.

Answer:

Si