Exploring Atomic Radius Trends in the Periodic Table

The video explores the concept of atomic size, initially addressing common misconceptions about atomic radius. It explains that electrons are not in fixed orbits but in orbitals, which are probability distributions. The video discusses methods to measure atomic size, such as the Van der Waals and covalent radius. It also examines trends in atomic size across the periodic table, noting that atomic size decreases across a period and increases down a group.

What is the initial misconception about the movement of electrons around the nucleus?

• Electrons are not present around the nucleus.

• Electrons move in a straight line around the nucleus.

• Electrons are stationary around the nucleus.

• Electrons are in fixed orbits like planets around the sun.

How are electron orbitals best described?

• Fixed paths around the nucleus.

• Probability distributions of where electrons can be.

• Solid spheres around the nucleus.

• Randomly scattered points around the nucleus.

What is the Van der Waals radius?

• The distance between two bonded atoms.

• Half the distance between the nuclei of two non-bonded atoms of the same element.

• The radius of a single atom.

• The distance between the nucleus and the outermost electron.

How is the covalent radius determined?

• By measuring the distance between two non-bonded atoms.

• By measuring the diameter of an atom.

• By measuring the distance between the nucleus and the outermost electron.

• By taking half the distance between the nuclei of two bonded atoms.

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

• It fluctuates randomly.

• It increases.

• It decreases.

• It remains the same.

Why does atomic size decrease across a period?

• Because the atoms lose electrons.

• Because the increased positive charge in the nucleus pulls the electron cloud closer.

• Because the number of protons and electrons decreases.

• Because the number of electron shells decreases.

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Which element has the smallest atomic radius?

• Neon

• Hydrogen

• Lithium

• Helium

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What happens to atomic size as you move down a group in the periodic table?

• It increases.

• It decreases.

• It remains the same.

• It fluctuates randomly.

Why does atomic size increase as you move down a group?

• Because the number of protons decreases.

• Because the number of electron shells increases.

• Because the nucleus gets smaller.

• Because the atoms lose electrons.

Where are the largest atoms found in the periodic table?

• Top right

• Bottom left

• Top left

• Bottom right