I think ethers are being referred to in this questions since an ether is defined by having a oxygen atom that is directly bonded to carbons on both sides.
I hope this helps. Let me know if you any further questions or if you anything to be clarified.
The volume of the gas mixture is 1.7 L and its total pressure is 0.810 atm. ... If the carbon and oxygen react completely to form CO(g), what will be the final .... acid to generate hydrogen gas, which is collected over a liquid whose vapor ..... It takes more energy to add an electron to fluorine than to oxygen because the radius
Answer:
Astatine is a halogen with several isotopes that all have short half-lives.
Which of the following combinations of mass number and neutrons are possible as isotopes of astatine? Choose one or more:
i) A = 211, n = 127
ii) A = 210, n = 125
iii) A = 220, n = 134
iv) A = 207, n = 122
v) A = 209, n = 124
Explanation:
The mass number is the sum of the number of protons and the number of neutrons in an atom.
Atomic number of At(astatine ) =85
That means it has --- 85protons.
Its mass number A=210
Hence, the number of neutrons in At are:

Second option:
ii) A=210 , n=125 is the answer.
Answer:
The answer to your question is the second choice
Explanation:
Formula to calculate the heat of any substance
Q cal= mCcal ΔTcal
Formula to calculate the heat of a metal. The heat will be negative because it releases heat.
Qm = -mCmΔTm
Now equal both formula
Qcal = Q m
mCcalΔTm = -mCmetΔTmet
-Solve for Cmet
Cmet = -[mCcalΔTm] / mΔTmet