1. Green patches appear on the surface of a metallic statue in a museum. It can be deduced that the statue may contain
A. tin
B. iron
C. silver
D. copper
Why the answer is D?
2. Which of the following statements concerning a water molecule is / are correct?
(1) The number of bonding electrons contributed by each hydrogen atom in the molecule is 2.
(2) the number of bonding electrons contributed by the oxygen atom is 2.
(3) the total number of electrons in the molecule is 8
Why the answer is (2) only?
Thx a lot!!!
F5 chem help plz
2014-08-25 2:29 am
回答 (2)
2014-08-25 2:53 am
✔ 最佳答案
1.Metallic statue --> oxidize
Tin oxidize forming black/white powder
Iron oxidize(rust) forming brown(Fe3+) powder/solid
Silver is resistant to oxidizing, should remain silvery.
Copper oxidize to form bluish green Cu2+ ions, which is the green patches
2.
(1) Each hydrogen atom can only contribute 1 electron
(2) Oxygen atom contributes 1 electron to each hydrogen atom,
oxygen atom bonds to 2 hydrogen atoms in total, so 1+1=2
(3) oxygen has 8 electrons, 2 hydrogen atoms have 2 electrons
10 electrons in total within the water molecule.
Hope this helps!
2014-08-25 5:10 am
1.
Copper is corroded in air to form patina (銅綠) which is green in colour. The formula of patina is CuCO3•Cu(OH)2.
Copper is corroded in air to form patina (銅綠) which is green in colour. The formula of patina is CuCO3•Cu(OH)2.
收錄日期: 2021-04-15 16:13:51
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