Срочно помогите !!!!!!

Question

Срочно помогите !!!!!!

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Answer 1

Ar = Mr
Ar(Au) = 197 
Ar(Mn) = 55 
Ar(Al) = 27 
Mr(Al2O3) = 2Ar(Al) + 3Ar(O) = 2*27 + 3*16 = 102
Mr(NaOH) = Ar(Na) + Ar(O) + Ar(H) = 23 + 16 + 1 = 40
Mr(CH4) = Ar(C) + 4Ar(H) = 12 + 4*1 = 16