Educated Guess Here!
Since Br-80 does not exist, maybe that means Br-79 or Br-81 have very unequal abundances. For example, Br-79 may have 75% abundance whereas Br-81 may have 25% abundance.
Answer:
since there is a decimal point at the end, they are all significant figures so the answer is 5
Organic chemical compounds as recommended by the (IUPAC)
Answer:
4- radioactive isotopes
Explanation:
I don't remember exactly but this question was on the regents
Answer:
1) The elements have filled valence levels.
Explanation:
Since they have filled valence levels, they're stable and don't need to electrons to fill their valence shells since they're already full.
2) False, They do have electrons
3) False, He does have only one electron shell, but going down the periods, every next element have one more electron shell than a preceding one has.
4)False, they're actually the smallest atoms of their respective period
