Question

please please help me fast​

Answer 1

Answer:

6)atomic number of sodium is 11 mass number is 23

7)Cobalt therapy is the medical use of gamma rays from the radioisotope cobalt-60 to treat conditions such as cancer. Beginning in the 1950s, cobalt-60 was widely used in external beam radiotherapy (teletherapy) machines, which produced a beam of gamma rays which was directed into the patient's body to kill tumor tissue.

8)valency of neon is 0 because it has completely filled valence{outermost} shell i.e. 8 electrons and so it is stable

Answer 2

Answer:

1. ATOMIC NUMBER-11,MASS NUMBER 23
2. Iodine 131 is used in the treatment of cancer.
3. 0.....