Which of the folllowing is NOT a mixture? A. table salt
B. lemonade
C. garden soil
D. salad dressing

Table salt, because it’s a pure substance.
Lemonade has water/ice, lemons and sugar
Garden soil has different soils and dirts and nutrients
Salad dressing has salt, usually seeds/specks and it’s made of a creamy substance
It’s table salt because table salt is pure and is made of the element “na”

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.