What is the primary reason for the increase in ionization energy across a period?
Practice Questions
1 question
Q1
What is the primary reason for the increase in ionization energy across a period?
Increased nuclear charge
Decreased electron shielding
Increased atomic radius
Decreased electronegativity
As you move across a period, the nuclear charge increases while the shielding effect remains relatively constant, leading to higher ionization energy.
Questions & Step-by-step Solutions
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Q
Q: What is the primary reason for the increase in ionization energy across a period?
Solution: As you move across a period, the nuclear charge increases while the shielding effect remains relatively constant, leading to higher ionization energy.
Steps: 7
Step 1: Understand what ionization energy is. It is the energy required to remove an electron from an atom.
Step 2: Know that a 'period' refers to a row in the periodic table where elements have the same number of electron shells.
Step 3: Recognize that as you move from left to right across a period, the number of protons in the nucleus increases. This is called 'nuclear charge.'
Step 4: Realize that more protons mean a stronger positive charge in the nucleus, which pulls electrons closer to the nucleus.
Step 5: Understand that the 'shielding effect' is the phenomenon where inner electrons block the outer electrons from the full effect of the nuclear charge. This effect stays relatively constant across a period.
Step 6: Combine these ideas: with more protons (higher nuclear charge) and a constant shielding effect, the outer electrons feel a stronger attraction to the nucleus.
Step 7: Conclude that because the outer electrons are held more tightly, it takes more energy to remove them, resulting in higher ionization energy as you move across a period.
