Atomic Radius Trends and Orbital Shapes in the Periodic Table

The video tutorial explains the concept of atomic orbitals, emphasizing that electrons travel in orbitals rather than fixed orbits. It introduces the atomic radius, a measure of the distance from the nucleus to the electron cloud boundary, and discusses how it is influenced by the number of protons and electrons. The tutorial explores trends in atomic radius both down a group and across a period in the periodic table, highlighting the effects of electron shells, effective nuclear charge, and electron shielding. Examples of elements like lithium and beryllium are used to illustrate these concepts.

What is the primary difference between an electron's orbit and an orbital?

• Orbits are probability distributions, while orbitals are fixed paths.

• Orbits are fixed paths, while orbitals are probability distributions.

• Orbits are only found in hydrogen atoms.

• Orbits and orbitals are the same.

What does the atomic radius measure?

• The number of protons in an atom.

• The distance from the nucleus to the outermost electron cloud.

• The distance between two atoms.

• The number of electron shells in an atom.

As you move down a group in the periodic table, what happens to the atomic radius?

• It fluctuates randomly.

• It increases.

• It decreases.

• It remains the same.

Why does the atomic radius increase as you move down a group?

• Because the number of electron shells increases.

• Because the number of protons decreases.

• Because the effective nuclear charge decreases.

• Because the atomic mass decreases.

What happens to the atomic radius as you move across a period from left to right?

• It decreases.

• It fluctuates.

• It remains constant.

• It increases.

What is the main reason for the decrease in atomic radius across a period?

• Increase in electron shielding.

• Decrease in atomic mass.

• Increase in effective nuclear charge.

• Decrease in electron shells.

How does electron shielding affect atomic radius?

• It decreases the atomic radius.

• It has no effect on atomic radius.

• It causes the atomic radius to fluctuate.

• It increases the atomic radius.

What is the atomic number of lithium?

• 4

• 3

• 2

• 1

In the comparison between lithium and beryllium, what remains the same?

• Number of electron shells.

• Number of protons.

• Number of valence electrons.

• Number of electron shielding electrons.

Why does beryllium have a smaller atomic radius than lithium?

• Because it has more valence electrons.

• Because it has fewer protons.

• Because it has more electron shells.

• Because it has a higher effective nuclear charge.