The following table represents the first three periods of the modern periodic table . Study the table and answer the questions that follow:
Name the element which has the highest ionisation energy.

Explanation

To determine the element with the highest ionization energy from the first three periods of the modern periodic table, we can follow these steps:

### Step 1: Understand Ionization Energy
Ionization energy is the energy required to remove an electron from an atom in its gaseous state. Generally, ionization energy increases across a period and decreases down a group in the periodic table.

### Step 2: Analyze the Trends in Ionization Energy
- **Across a Period (Left to Right)**: Ionization energy increases. This is because as you move from left to right, the atomic number increases, leading to a greater positive charge in the nucleus. This increased nuclear charge attracts the electrons more strongly, making it harder to remove an electron.
- **Down a Group (Top to Bottom)**: Ionization energy decreases. This is due to the increase in atomic size; as you move down a group, additional electron shells are added, which increases the distance between the nucleus and the outermost electrons. This makes it easier to remove an electron.
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