1. Give a chemical for the following
(a) A solid non-metal element which conducts electricity
(b)A black semi-metal
2. For each of the following groups of substances, idenity one substance which is different from the others. Explain your choice.
(a) boron, cobalt, silicon, selenium
(b)water, ethanol, sodium chloride, diamond
(c)stell, iron, chlorine, agron
(d)potassium, calcium, hassium, gold
3. Suppose that you have a gold coin and a brass coin. (Brass is an alloy of copper and zinc). They both look golden and are hard to distinguish. If you are provived with a microscope which allows you to view the individual atoms in each coin, explain how you can tell which is which.
F.3 Chem.
2011-02-24 2:59 am
回答 (4)
2011-02-25 2:37 am
✔ 最佳答案
1 a)graphiteb)boron
2 a) cobalt,because only cobalt is not a semi-metal
b)diamond,because only it formed by one element
c)steel,because only steel is not a element
d)hassium, because only it doesn't have neturons
3 Gold is an element but brass is not. thus, we can see only one type of atom when the gold coin is under the microscope and the brass coin with more than one type.
參考: Myself
2016-10-10 3:26 pm
hah
2011-02-24 6:32 am
1a) Graphite, because of the presence of delocalized electrons betweem graphite layers
1b)Boron
2a) Cobalt, only cobalt is not a semi-metal
2b) Diamond, only diamond is made up of a single type of element(carbon)
2c) Steel, only steel is not an element( It is an alloy made up of Iron and Carbon)
2d) Hassium, only hassium is a synthetic element.(Others can be found in nature in forms of compounds[potassium and calcium], while gold can be found in nature)
3) As brass is an alloy, it consists of atoms of copper and zinc. We can see a regular packaging of atoms in gold, while an irregular packaging of atoms can be seen in brass, as it copper and zinc have different atomic sizes.
其實2果條分別有好多種答法...例如(2b)可以話只有NaCl係ionic compound.
1b)Boron
2a) Cobalt, only cobalt is not a semi-metal
2b) Diamond, only diamond is made up of a single type of element(carbon)
2c) Steel, only steel is not an element( It is an alloy made up of Iron and Carbon)
2d) Hassium, only hassium is a synthetic element.(Others can be found in nature in forms of compounds[potassium and calcium], while gold can be found in nature)
3) As brass is an alloy, it consists of atoms of copper and zinc. We can see a regular packaging of atoms in gold, while an irregular packaging of atoms can be seen in brass, as it copper and zinc have different atomic sizes.
其實2果條分別有好多種答法...例如(2b)可以話只有NaCl係ionic compound.
參考: 自己
2011-02-24 3:25 am
1 a)graphite
b)boron
2 a) cobalt,only cobalt is not a semi-metal
b)diamond,only it formed by one element
c)steel,only steel is not a element
d)gold,it is the least reactive element
3)maybe you will see the gold atom that is the biggest
b)boron
2 a) cobalt,only cobalt is not a semi-metal
b)diamond,only it formed by one element
c)steel,only steel is not a element
d)gold,it is the least reactive element
3)maybe you will see the gold atom that is the biggest
收錄日期: 2021-04-13 17:50:41
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