Alkali metals are a group of elements in the Periodic Table.
a) What is common to the atoms of alkali metals?
b) Describe its overall trend of density down the group.
c) Explain why they appear silvery white only after they are freshly cut.
d) Describe its reactivity down the group.
e) A small priece of sodium metal is added into water.
i) What do you observe?
ii) Is the solution formed acidic,neutral or alkaline?
chemistry
2007-09-15 6:44 pm
回答 (2)
2007-09-15 7:39 pm
✔ 最佳答案
a)they have the same no. of outermostshell electronsb)decrease down the group
c)they are very reactive which react with oxygen in air to form a oxide layer
d)increase down the group
e)i)effervescence(泡騰) occur,the sodium metal change in a silvery ball float on water surface and move very fast .Finally dissolved.
ii)alkaline(sodium metal react with water to give out hydorgen gas and sodium hydroxide )
參考: 自己
2007-09-16 6:12 pm
a)
They all have 1 outermost shell electron
b)
I am not sure
c)
As they are metals, they are silvery when fresh cut. However, they are very reactive, they react with oxygen and from an oxide layer very soon. The oxide layer appears dull.
d)
Reactivity of Group 1 increases down the group
ei)
Sodium melts into a silvery ball which moves quickly on water surface, some colourless gas bubbles com out.
eii)
Alkaline. Because Group 1 metals are called 'Alkali metals', i.e. they form alkaline soultions with water
They all have 1 outermost shell electron
b)
I am not sure
c)
As they are metals, they are silvery when fresh cut. However, they are very reactive, they react with oxygen and from an oxide layer very soon. The oxide layer appears dull.
d)
Reactivity of Group 1 increases down the group
ei)
Sodium melts into a silvery ball which moves quickly on water surface, some colourless gas bubbles com out.
eii)
Alkaline. Because Group 1 metals are called 'Alkali metals', i.e. they form alkaline soultions with water
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