Question

-77. In 2002, a team of scientists from Russia and the United States reported the creation of the first atom of element 118, which is named oganesson, and whose symbol is Og. The synthesis involved the collision of californium-249 atoms with accelerated ions of an atom which we will denote X. In the synthesis, an oganesson-294 is formed together with three neutrons. 24.0f + x => 19 Og + 3 in 1991 (a) What are the identities of isotopes X? (b) Isotope X is unusual in that it is very long-lived (its half-life is on the order of 1019 yr) in spite of having an unfavorable neutron-to-proton ratio (Figure 21.1). Can you propose a reason for its unusual stability? (c) Oganesson-294 decays! into livermorium-290 by alpha decay. Write a balanced equation for this.

Answer 1

77 (a)

A CF + x +og+3n

The sum of atomic numbers on left hand side = the sum of atomic numbers on right hand side

98 + Z = 118 +3(0) Z = 20

The sum of mass numbers on left hand side = the sum of mass numbers on right hand side

29 Cf + X Og +36n249 + A = 294 + 3(1) A = 48

Hence, the isotope X is $_{20}^{48}Ca$

It is an isotope of calcium

(b)

The unusual stability of $_{20}^{48}Ca$ is due to magic number of protons. Number of protons in $_{20}^{48}Ca$ is 20 which is a magic number. Nuclei with magic number of protons (2,8, 20, 28, 50, 82 and 126) are exceptionally stable due to large energy gap between a series of filled energy level and next empty level,

(c)

fog +20 Li + He

Let Z be the atomic number of Livermorium.

The sum of atomic numbers on left hand side = the sum of atomic numbers on right hand side

118 = 2 + 2 Z = 116

Hence, the balanced equation is

og + Li + He