The Periodic Table and Atomic Structure

Which statements are true concerning elements in the same group of the periodic table?
Select all that apply.

• They are all metals or nonmetals, but not both.

• They have the same number of shells of electrons.

• They have the same number of inner core electrons.

• They have the same outer shell electron configuration.

• They have similar periodic properties.

Tags

HS-PS1-A-2

The valence electrons of an atom do not experience the full attractive force of protons in the atom’s nucleus due to the presence of inner core electrons. The reduction in nuclear charge experienced by valence electrons due to inner core electrons is called the

• shielding effect.

• nuclear charge effect.

• ionization energy effect.

• periodic law effect.

Tags

HS-PS1-A-3

The effective nuclear charge, Z_eff, experienced by valence electrons in an atom can be estimated from the equation:

Z_eff = the number of protons – the number of core electrons

Using this estimation, effective nuclear charge for Main Group elements would ​ (a)   left to right across a period and ​ (b)   down a group.

• increase
• remain the same
• decrease

A Main Group element has 81 protons and an estimated effective nuclear charge of +3. Therefore, the element has ​ (a)   core electrons and can be found in Group ​ (b)   of the Periodic Table.

• 78
• 84
• 81
• 3A
• 5A
• 2A

The diagram shows the electron structures of two alkali metals and two halogens. When these elements react and form compounds, alkali metals lose their one valence electron while halogens gain one additional electron to their valence shell. The vigor of the reaction is directly related to the distance of the valence electrons from the attractive pull of the atom’s nucleus. For alkali metals, it becomes easier to lose the valence electron with increasing distance of that electron from the attractive pull of the nucleus. For halogens, it becomes easier to gain an additional electron to the valence shell with decreasing distance of that shell to the attractive pull of the atom’s nucleus.

For the given elements, which reaction will proceed most quickly or be the easiest?

• Lithium (Li)

• Sodium (Na)

• Fluorine (F)

• Chlorine (Cl)