Turn on thread page Beta
    • Thread Starter
    Offline

    14
    ReputationRep:
    Name:  Screen Shot 2016-10-30 at 23.18.11.png
Views: 66
Size:  21.8 KB

    does anyone know the answer is 1,2 and 5

    and not 1,2 and 4
    Offline

    1
    ReputationRep:
    From the electron configuration we know that the element has 19 electrons therefore it is Potassium (K)
    Metals reacts with oxygen to form a metal oxide therefore 5 is correct. 4K + O2 = 2K2O
    The element above Potassium is Sodium. Potassium is more reactive than sodium because there is greater shielding as there is one greater oribital than sodium. Therefore 4 is incorrect.
    Offline

    13
    ReputationRep:
    (Original post by medhelp)

    does anyone know the answer is 1,2 and 5

    and not 1,2 and 4
    The reactivity of alkali metals, such as potassium in this case, is dependent on its ability to lose an electron. As you go down group 1, the atomic radius gets bigger, there is more electron shielding and hence there is a smaller force between the valence (outermost) electron and the nucleus - hence the valence electron is lost more easily. Therefore 4 is incorrect because reactivity increases as you go down group 1.
    • Thread Starter
    Offline

    14
    ReputationRep:
    (Original post by Jpw1097)
    The reactivity of alkali metals, such as potassium in this case, is dependent on its ability to lose an electron. As you go down group 1, the atomic radius gets bigger, there is more electron shielding and hence there is a smaller force between the valence (outermost) electron and the nucleus - hence the valence electron is lost more easily. Therefore 4 is incorrect because reactivity decreases as you go down group 1.
    but if reactivity decreases down the group, the element above X will be more reactive than X... ?
    If an electron is more easy to lose that = more reactive ?

    (Original post by LelouchViBrit)
    From the electron configuration we know that the element has 19 electrons therefore it is Potassium (K)
    Metals reacts with oxygen to form a metal oxide therefore 5 is correct. 4K + O2 = 2K2O
    The element above Potassium is Sodium. Potassium is more reactive than sodium because there is greater shielding as there is one greater oribital than sodium. Therefore 4 is incorrect.
    you're not allowed a periodic table for this question :/ I guess I could've figured out it's a metal because 1 electron in its outer shell = group 1
    so reactivity increases as you go down group 1?

    Also I can only find the reactivity series in a really simple form: K Na Li Ca Mg Al (decreasing) so you can you please check this:

    (more reactive to least reactive)

    Fr
    Cs
    Rb
    K
    Na
    Li
    Ra
    Ba
    Sr
    Ca
    Mg
    Be
    Al

    carbon

    Zn
    Fe

    hydrogen

    Tin (can't remember symbol)
    Pb
    Cu
    Ag
    Au
    Platinum (can't remember symbol)
    Offline

    13
    ReputationRep:
    (Original post by medhelp)
    but if reactivity decreases down the group, the element above X will be more reactive than X... ?
    If an electron is more easy to lose that = more reactive ?



    you're not allowed a periodic table for this question :/ I guess I could've figured out it's a metal because 1 electron in its outer shell = group 1
    so reactivity increases as you go down group 1?

    Also I can only find the reactivity series in a really simple form: K Na Li Ca Mg Al (decreasing) so you can you please check this:

    (more reactive to least reactive)

    Fr
    Cs
    Rb
    K
    Na
    Li
    Ra
    Ba
    Sr
    Ca
    Mg
    Be
    Al

    carbon

    Zn
    Fe

    hydrogen

    Tin (can't remember symbol)
    Pb
    Cu
    Ag
    Au
    Platinum (can't remember symbol)
    I meant to say reactivity INCREASES as you go down group 1
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: October 31, 2016
The home of Results and Clearing

3,090

people online now

1,567,000

students helped last year

University open days

  1. Bournemouth University
    Clearing Open Day Undergraduate
    Wed, 22 Aug '18
  2. University of Buckingham
    Postgraduate Open Evening Postgraduate
    Thu, 23 Aug '18
  3. University of Glasgow
    All Subjects Undergraduate
    Tue, 28 Aug '18
Poll
How are you feeling about GCSE results day?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.