D: Determine which of the following electron configurations represents an element with lower reactivity compared to the other element. Record the period and group of that element in the grid, putting period number first, followed by a space, followed by the group number.
1s^2 2s^2 2p^6 3s^2 3p^2
1s^2 2s^2 2p^6

"the periodic table is arranged in order of atomic number."

the answers would be

the first one and the second one

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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