Explain the general trend in first ionisation energy across period 2 in the periodic table.
Across period 2, the nuclear charge increases from Li (3+) to Ne (10+) as protons are added to the nucleus. - The electros are removed from the same main energy level and electrons in the same main energy level do not shield each other well. - Therefore, the force of attraction, from the nucleus, on the outer electrons increases from left to right across the period and the outer electron is more difficult to reove for neon. - The neon atom is smaller than the lithium atom and, therefore, the outer electron is closer to the nucleus amd more strongly held.