Periodic Trends: Atomic Radius and Ionization Energy

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What is the atomic radius?

The atomic radius is the distance from the nucleus of an atom to the outermost electron shell.

How does atomic radius change across a period?

The atomic radius decreases across a period from left to right due to increased nuclear charge.

Why does the atomic radius decrease across a period?

Increasing nuclear charge pulls electrons closer to the nucleus, reducing the atomic radius.

How does atomic radius change down a group?

The atomic radius increases down a group because additional electron shells are added.

What is ionization energy?

Ionization energy is the amount of energy required to remove an electron from an atom in the gaseous state.

How does ionization energy change across a period?

Ionization energy generally increases across a period as nuclear charge increases, making it harder to remove an electron.

Why does ionization energy increase across a period?

Increased nuclear charge holds electrons more tightly, requiring more energy for removal.

How does ionization energy change down a group?

Ionization energy decreases down a group as electrons are further from the nucleus and are more easily removed.

What is the effect of shielding on atomic radius?

Increased electron shielding down a group reduces effective nuclear charge, increasing atomic radius.

What is successive ionization energy?

Successive ionization energy refers to the energy required to remove additional electrons after the first one.

Why is the second ionization energy generally higher than the first?

The second ionization energy is higher because it requires removing an electron from a positively charged ion, which is harder.

How do cations and anions affect atomic radius?

Cations decrease in atomic radius due to loss of electrons, while anions increase in radius due to gaining electrons.

Why do transition metals have similar atomic radii?

Transition metals have similar atomic radii due to the filling of the d-subshell, which approximates nuclear charge.

What is the trend in ionic radius down a group?

Ionic radius increases down a group as atoms have more electron shells.

Why is ionization energy important in chemical reactions?

Ionization energy indicates how readily an atom can lose an electron, influencing its reactivity and bonding.