Please help me urgently is for a test and I need to do this homework and i don’t understand

Explanation

TIP:

group 1= 1 valence

group 2= 2valence

group 3- 12 vary depending on the charge

group 13= 3 valence

group 14= 4 valence

group 15= 5 valence

group 16= 6 valence

group 17= 7 valence

group 18= 8 valence (a full shell) they don't bond they're noble gases

This should tell u the valences :) it says the group on the top of your picture just look at the small text.

The dot structure:

1. write the symbol for example Zinc is Zn.

Zinc has 2 valence electrons (you can figure out the valence of transition metals by doing the electron config but that's painful and annoying so i'm just going to tell u it)

Imagine the symbol Zn has a border on it like a square. each side can ONLY have 2 dots MAXIMUM!! therefore its dot structure will look like:

:Zn   (it doesn't matter what side you put them on, if it were 3 valence just add a lonely dot on an empty side and so on so forth)  

Hope i helped

b is the correct

consider the reaction below.

 no rx

at 500 k, the reaction is at equilibrium with the following concentrations.

[pci5]= 0.0095 m

[pci3] = 0.020

[ci2] = 0.020 m

what is the equilibrium constant for the given reaction?

0.042

0.42

2.4

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