Answer :
Answer:
The missing nucleus is carbon-12:
- [tex]^{12}_6C[/tex]
Explanation:
The nuclear reaction given is:
[tex]^{249}_{98}Cf[/tex] + ___ → [tex]^{257}_{104}Rf+4^1_0n[/tex]
To balance this equation you must add a nucleus which contains the missing mass and atomic numbers.
Mass number is the number of protons plus neutrons and is the superscript to the left of the chemical symbol: 249 for Cf, 257 for Rf, and 1 for n (neutron).
Atomic number is the number of protons and is the subscript to the left of the chemical symbol: 98 for Cf, 104 for RF and 0 for n.
Thus, the balance is:
Mass number:
- 249 + A = 257 + 4 × 1
- 249 + A = 257 + 4
- 249 + A = 261
- A = 261 - 249
- A = 12
Atomic number:
- 98 + Z = 104 + 4×0
- 98 + Z = 104
- Z = 104 - 98
- Z = 6
Then, you are looking for a nucleus (or gropu of nuclei) which supply 6 protons and 6 neutrons. That is a nucleus of carbon-12: [tex]^{12}_6C[/tex].
The balanced nuclear reaction is:
[tex]^{249}_{98}Cf+^{12}_{6}C[/tex] → [tex]^{257}_{104}Rf+4^1_0n[/tex]