Periodic Trends

What happens to the atomic radius as you go down the group?

• the radius increases

• the radius decreases

• the radius remains the same

• nothing happens

If the radius increases as you go down the group, explain why this happens.

Answer explanation

Moving down the group, atomic radius increases due to additional energy levels being added with each new period.

What happes to the atomic radius as the atomic number increases across the period?

• the atomic radius decreases

• the atomic radius increases

• the atomic radius stays the same

• nothing happens

Tags

NGSS.HS-PS1-1

If the atomic radius decreases as the atomic number increases, explain why this happens.

Answer explanation

Moving across the period, te number of protons increases, the number of energy levels stay the same and the nuclear charge increases pulling the electrons in closer

Tags

NGSS.HS-PS1-1

Metals lose electrons to form cations. Do the cations have a larger or smaller ionic radius than the neutral atom from which they were formed?

• smaller

• bigger

Cations have a smaller ionic radius than the neutral atom from which they were formed. Explain why.

Answer explanation

With the loss of valence electrons, the outer energy level is lost, and there are more protons than electrons. The nuclear charge pulls electrons in closer = smaller radius.

Tags

NGSS.HS-PS1-1

Nonmetals gain electrons to form anions. Do anions have a larger or smaller ionic radius than the neutral atom from which they were formed?

• smaller

• larger

If anions have a larger radius than the neutral atom from which they were formed, why does this happen?

Answer explanation

By gaining electrons, the ions will have more electrons than protons. The repulsive forces increase making the anion larger than its neural atom.

Tags

NGSS.HS-PS1-1

Which of the following elements has the smallest atomic radius?

• Li

• P

• O

• S

Tags

NGSS.HS-PS1-1

Which of the following elements has the largest atomic radius?

• Cl

• S

• Br

• As