S3.1 Periodic Table

Carbon and silicon belong to the same group of the periodic table. Distinguish between the terms group and period in terms of electron arrangement.

• Group refers to the vertical columns in the periodic table, while period refers to the horizontal rows.

• Group refers to the horizontal rows in the periodic table, while period refers to the vertical columns.

• Group and period have the same meaning in terms of electron arrangement.

• Group and period have no relation to electron arrangement.

Carbon and silicon belong to the same group of the periodic table. State the period numbers of both carbon and silicon.

• Carbon belongs to period 2 and silicon belongs to period 3.

• Carbon belongs to period 3 and silicon belongs to period 4.

• Carbon belongs to period 4 and silicon belongs to period 5.

• Carbon belongs to period 5 and silicon belongs to period 6.

An atom of an element contains 19 electrons. In which group of the periodic table does it occur?

• Group 1

• Group 2

• Group 5

• Group 7

An element is in group 14 and period 3 of the periodic table. How many electrons are in the highest occupied energy level of an atom of this element?

• 3

• 4

• 12

• 14

Which statements about atomic structure and the periodic table are correct?

I. An element in group 2 has 2 electrons in its valence (outer) energy level.

II. An element in period 3 has electrons in 3 energy levels.

III. The element in group 2 and period 3 has an atomic number of 12.

• I and II only

• I and III only

• II and III only

• I, II and III

What is the correct electron configuration of the Cu⁺ ion?

• [Ar]3d⁹4s¹

• [Ar]3d⁷4s²

• [Ar]3d¹⁰

• [Ar]3d⁸4s¹

Which species has the electron configuration of 1s²2s²2p⁶3s²3p⁶3d⁸

• Ni

• Ni²+

• Fe

• Cu²+

Element X is in group 15 and period 4 of the periodic table. Which statement is correct?

• X has 5 occupied energy levels.

• X can form ions with 3- charge.

• X is a transition element.

• X has 4 valence electrons.