Given the following electronic configurations, identify how many valence electrons each atom has. A=
Element
Electron Configuration
Number
of
Valence
Electrons
B =
C=
Sodium
(Na)
152 2s 2p 3s
А
DONE
Oxygen (0)
1s 2s 2p
B
Iron (Fe)
1s 2s 2p 3s 3p 452
306
С

sodium=atomic number 11 it electronic configuration is ,K=2, L=8,M=1 Valence is 1

oxygen= atomic number 8 it electronic configuration is K=2, L=6 Valence is 2

iron= atomic number 26 it electronic configuration is K= 2 L= 8,M=8 N=6 Valence 2

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.