Atomic Radii Trends and Effective Nuclear Charge in the Periodic Table

The video tutorial covers periodicity in the periodic table, focusing on atomic radii, ionisation energy, and electron affinity. It explains how atomic radii decrease from left to right due to increasing nuclear charge and shielding effects. Ionisation energy trends are discussed, highlighting the energy needed to remove electrons and how it increases across a period. Electron affinity is introduced, showing its increase across a period due to effective nuclear charge. The video also touches on ionic radii, comparing neutral atoms and cations.

What happens to atomic radii as you move from left to right across the periodic table?

• They fluctuate randomly.

• They increase.

• They decrease.

• They remain the same.

What is the effective nuclear charge?

• The charge of the outermost electron.

• The charge of the nucleus alone.

• The net positive charge experienced by an electron in a multi-electron atom.

• The total charge of all electrons in an atom.

What is ionisation energy?

• The energy required to split an atom into ions.

• The energy released when an electron is added to an atom.

• The energy required to remove an electron from a gas phase atom.

• The energy required to add an electron to an atom.

How does ionisation energy change as you move down a group in the periodic table?

• It decreases.

• It increases.

• It fluctuates.

• It remains constant.

Which elements are most easily ionised?

• Elements with half-filled outer shells.

• Elements with no valence electrons.

• Elements with one valence electron in an outer shell.

• Elements with full outer shells.

What is electron affinity?

• The energy required to split an atom into ions.

• The energy released when an electron is attached to an atom.

• The energy required to add a proton to an atom.

• The energy required to remove an electron from an atom.

How does electron affinity change as you move from left to right across the periodic table?

• It decreases.

• It increases.

• It fluctuates.

• It remains constant.

What is the relationship between neutral atoms and their cations in terms of size?

• Neutral atoms have no cations.

• Neutral atoms are larger than their cations.

• Neutral atoms are smaller than their cations.

• Neutral atoms and their cations are the same size.

What do ions with the same number of electrons as atomic neon have in common?

• They have the same mass.

• They have the same atomic number.

• They have the same electron configuration.

• They have the same chemical properties.

Why are neutral atoms larger than their cations?

• Because neutral atoms have fewer protons.

• Because cations have more electrons.

• Because cations have lost their outermost electron.

• Because neutral atoms have more protons.