Understanding Atomic Size and Trends

What is the primary reason that makes measuring the exact size of an atom challenging?

• Atoms are too small to be seen.

• Atoms have a fixed size.

• Atoms are not spherical.

• The electron cloud is defined by probability.

How is a non-bonding atomic radius determined?

• By measuring the distance between bonded atoms.

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

• By using the atomic number.

• By calculating the volume of the electron cloud.

What pattern is observed in atomic radii as you move across a period from left to right?

• Atomic radius fluctuates randomly.

• Atomic radius remains constant.

• Atomic radius decreases.

• Atomic radius increases.

Which element would have a larger atomic radius: cesium or lithium?

• It depends on the temperature.

• Both have the same atomic radius.

• Lithium

• Cesium

What happens to the principal quantum number as you move down a group in the periodic table?

• It increases.

• It remains the same.

• It fluctuates.

• It decreases.

Why do atoms get larger as you move down a group in the periodic table?

• The number of protons increases.

• The outermost electrons are in larger orbitals.

• The atomic mass increases.

• The number of neutrons increases.

What is the effect of shielding on valence electrons?

• It increases the attraction to the nucleus.

• It decreases the attraction to the nucleus.

• It has no effect on the attraction to the nucleus.

• It makes the electrons more reactive.

How is effective nuclear charge calculated?

• By multiplying the core electron charge with the nuclear charge.

• By dividing the nuclear charge by the number of electrons.

• By subtracting the core electron charge from the nuclear charge.

• By adding the core electron charge to the nuclear charge.

What is the trend in effective nuclear charge as you move across a period?

• It increases.

• It fluctuates.

• It remains constant.

• It decreases.

Why does the atomic radius decrease as you move from left to right across a period?

• The effective nuclear charge increases.

• The number of electron shells decreases.

• The number of neutrons increases.

• The atomic mass decreases.