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. which statements would be expected to be true for oganesson? select all that apply. it has a full valence shell of electrons. it has the largest atomic radius of the four new elements. it has a high electron affinity. it is relatively unreactive. it has the lowest effective nuclear charge of the four new elements.

Explanation:

Noble gases have full - valence electron shells, which makes them relatively unreactive. Atomic radius decreases across a period, so Oganesson does not have the largest atomic radius among the four new elements. Noble gases have low electron affinities as they already have stable electron configurations. Effective nuclear charge increases across a period, so Oganesson does not have the lowest effective nuclear charge.

Answer:

It has a full valence shell of electrons.
It is relatively unreactive.