Trends in the Periodic Table

As you move from left to right across each row of the Periodic Table, the size of an atom

• Decreases because additional protons and electrons are added to the same principal energy level, resulting in more forces of attraction and pulling the electrons closer to the nucleus.

• Increases because electrons are added to energy levels further away from the nucleus, which results in electron shielding.

• Decreases because electrons are more easily lost.

• Increases because additional neutrons added to the nucleus interfere with the forces of attraction between the protons and electrons.

As you move from top to bottom down the Alkali Metal group of the Periodic Table, the size of an atom

• Decreases because additional protons and electrons are added to the same principal energy level, resulting in more forces of attraction and pulling the electrons closer to the nucleus.

• Increases because electrons are added to energy levels further away from the nucleus, which results in electron shielding.

• Decreases because electrons are more easily lost.

• Increases because additional neutrons added to the nucleus interfere with the forces of attraction between the protons and electrons.

Why is the second ionization energy always greater than the first ionization energy for any element?

• The charge on the ion has become more positive, causing an increased attraction of the positively charged nucleus for the decreasing number of electrons.

• The charge on the ion has become more positive, causing a decreased attraction of the positively charged nucleus for the increasing number of electrons.

• The charge on the ion has become more negative, causing an increased attraction of the positively charged nucleus for the decreasing number of electrons.

• The charge on the ion has become more negative, causing a decreased attraction of the positively charged nucleus for the increasing number of electrons.

The size of an atom when it is converted to a cation gets

• Larger, because the repulsion due to additional electrons being added increases, pushing them further away from the nucleus.

• Smaller, because the loss of valence electrons causes an increased attraction by the positively charged nucleus for the remaining electrons.

The size of an atom when it is converted to an anion gets

• Smaller, because the loss of valence electrons causes an increased attraction by the positively charged nucleus for the remaining electrons.

• Larger, because the repulsion due to additional electrons being added increases, pushing them further away from the nucleus.

Down a group, ionization energy

• Decreases, because electrons are closer to one another and require more energy to remove.

• Increases, because electrons are closer to the nucleus and thus require more energy to remove.

• Decreases, because electrons are further away from the nucleus and thus require less energy to remove.

• Increases, because the number of protons increases, making it more difficult to lose electrons because they are being pulled closer.

As you move from left to right across each row of the Periodic Table, ionization energy

• Decreases, because additional protons are being added to the same principal energy level, leading to a weaker attraction for the electrons to the positively charged nucleus.

• Decreases, because additional electrons are being added to different principal energy levels, leading to a weaker attraction for the electrons to the positively charged nucleus.

• Increases, because additional protons are being added to the same principal energy level, leading to a greater attraction for the electrons to the positively charged nucleus.

• Increases, because additional electrons are being added to different principal energy levels, leading to a weaker attraction for the electrons to the positively charged nucleus.

Which statement best describes Alkaline Earth (Group II) Metals as they are considered from the top to the bottom of the Periodic Table?

• The number of principal energy levels increases, and the number of valence electrons increases.

• The number of principal energy levels increases, and the number of valence electrons remains the same.

• The number of principal energy levels remains the same, and the number of valence electrons increases.

• The number of principal energy levels remains the same, and the number of valence electrons decreases.

Which sequence of elements is arranged in order of decreasing atomic radii?

• Al, Si, P

• Li, Na, K

• Cl, Br, I

• N, C, B

Which sequence correctly places the elements in order of increasing ionization energy?

• H, Li, Na, K

• I, Br, Cl, F

• O, S, Se, Te

• H, Be, Al, Ga