Noble Gases more often than not don't respond on the grounds that they don't tend to pick up or lose electrons. Salt and Alkaline Earth Metals are delicate and soften at low temperatures. Incandescent lamp are extremely receptive nonmetals since they effortlessly acknowledge electrons from different components.
Since we're talking about a chain reaction, I think this would be a) self-sustaining. Chain reactions are not usually described as "weak" and can be highly explosive depending upon the compounds (think Uranium!).
The first (artificial) self-sustaining nuclear reaction is attributed to Enrico Fermi in 1942. Here's a bit of history:
http://www.atomicarchive.com/History/firstpile/firstpile_01.shtml
In carbohydrates the C:H:O is 1:2:1
Answer:
Kr
Explanation:
The noble gas that is isoelectronic with Br⁻ is krypton.
This is because krypton is the closest noble gas to Br on the periodic table.
Electronic configuration of Bromine is;
2, 8, 18, 7
Br⁻ becomes; 2, 8, 18, 8
Krypton is; 2, 8, 18, 8
(1) CaCO3 is the correct answer.
The type of bond formed between Ca2+ and CO3 2- is ionic, and the type of bond formed between C and O is covalent.
Hope this helps~