It’s [Xe]7s^2 5f^14 (first one) hopefully i could help!!
I think it is 75% sorry if I am wrong but if I am correct can I get brainlest?
Answer:
Answer to A. helium, neon, argon, krypton, xenon, and radon, B. Elemental hydrogen (H, element 1), nitrogen (N, element 7), oxygen (O, element 8), fluorine (F, element 9), and chlorine (Cl, element 17) are all gases at room temperature, and are found as diatomic molecules (H2, N2, O2, F2, Cl2). C. Elements Compounds
Ar (argon) HBr (hydrogen bromide) C 3H 8 (propane)
Kr (krypton) HI (hydrogen iodide) C 4H 10 (butane)
Xe (xenon) HCN (hydrogen cyanide)* CO (carbon monoxide)
Rn (radon) H 2S (hydrogen sulfide) CO 2 (carbon dioxide)
Explanation:
In the early 1900s, a scientist named Alfred Wegener noticed how the continents seem to fit together and developed the Theory of Continental Drift. Continental drift is the theory that continents can drift apart from one other and have done so in the past. Wegner's theory also explained why fossils of the same plant and animal species are found on both sides of the Atlantic Ocean. In addition similar types of rock and evidence of the same ancient climatic conditions are found on several continents.
Wegner hypothesized that all the separate continents of today were once joined in a single landmass that he called Pangaea.
207 is the mass number. 82 would be the atomic number