Atomic Size and Electron Behavior 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 radius and covalent radius. It then 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 common misconception about the movement of electrons around the nucleus?

• Electrons are not affected by the nucleus.

• Electrons move in a straight line.

• Electrons are stationary around the nucleus.

• Electrons move in fixed orbits like planets.

How are electron orbitals best described?

• As random points in space.

• As fixed paths around the nucleus.

• As probability distributions of electron locations.

• As solid spheres around the nucleus.

What is the Van der Waals radius?

• The distance between two bonded atoms.

• The radius of a single atom.

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

• The distance between the nucleus and the outermost electron.

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

• It fluctuates randomly.

• It remains constant.

• It decreases.

• It increases.

Why is helium smaller than hydrogen despite having more protons?

• Helium's electrons are more tightly attracted to the nucleus.

• Helium is a gas.

• Helium has fewer electrons.

• Hydrogen has a larger nucleus.

What is the effect of increased positive charge in the nucleus on atomic size?

• It decreases atomic size.

• It increases atomic size.

• It has no effect on atomic size.

• It makes the atom unstable.

What is the general trend in atomic size as you move down a group in the periodic table?

• Atomic size decreases.

• Atomic size fluctuates.

• Atomic size increases.

• Atomic size remains the same.

What causes the increase in atomic size as you move down a group?

• Addition of more protons.

• Addition of more electron shells.

• Decrease in nuclear charge.

• Increase in electron speed.

Which element is known to have the smallest atomic size?

• Beryllium

• Lithium

• Helium

• Hydrogen

Which part of the periodic table contains the largest atoms?

• Top right

• Bottom left

• Top left

• Bottom right