The value of zeff for a valence electron in an atom of silicon is?

Zeff is the effective nuclear charge wherein, Z resembles the number of protons in the nucleus while S corresponds to the number of non-valence electrons.

Zeff = Z - S

Silicon has 14 protons; its electron configuration is [Ne] 3s2 3p2. Its non-valence electrons is in the n = 1 and n =2 shells. There are 2 electrons in n = 1 and 8 in n = 2, so there are a total of 10 non-valence electron.

We will call D1 and D2 the volume of dextrose at 2.5% and 30% respectively

D1 + D2 = 500 (1)

D1*2,5/100 + D2*30/100 = 500*10/100 (2)

(2,5D1+30D2)/100 = 50

2,5D1 +30D2 = 50*100 = 5.000 (2)

D1 = 500 - D2 Now we clear D1 in (1)

2,5(500-D2) + 30D2 = 5.000 and we substitute in (2)

1.250 - 2,5D2 + 30D2 = 5.000

27,5D2 = 5.000 - 1.250 = 3.750

D2 = 3.750/27,5 = 136ml +4/11ml

D1 = 500ml - 136ml +4/11ml

D1 = 363ml +7/11ml

ANSWER 363ml+7/11 ml of dextrose 2,5% and 136ml+4/11 ml dextrose 30%