Question

in this performance task, you will answer 4 questions.
the united nations declared the year 2019 as the year of the periodic table. the year 2019 marks 150 years since the discovery of the periodic system of the arrangement of elements which led to the periodic table, mostly credited to dmitri mendeleev. since 1869, scientists have discovered or synthesized a number of new elements which exhibit properties in keeping with the logic of the arrangement of elements in the periodic table. like mendeleev, scientists have been able to predict the atomic number, placement in the periodic table, and properties of elements that had not yet been discovered or synthesized.
in 2016, the international union of pure and applied chemistry (iupac) announced the discovery of four new elements with atomic number, name, and symbol as follows:

• 113, nihonium, nh
• 115, moscovium, mc
• 117, tennessine, ts
• 118, oganesson, og

these new elements all occupy period 7 of the table, with oganesson (og) being a noble gas
the fact that the four new elements are period 7 of the table means that they all
○ have seven valence electrons
○ have seven shells of electrons
○ have an effective nuclear charge of 7+
○ form ions with charges of 7+

Explanation:

In the periodic table, the period number indicates the number of electron shells an element has. So, elements in Period 7 have seven electron shells. Valence electrons depend on the group (not period). Effective nuclear charge is a more complex concept not simply equal to the period number. And forming ions with \(7+\) charge is not a general property of Period 7 elements.

Answer:

have seven shells of electrons