Astudent placed 18.5 g of glucose (c6h12o6) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100.-ml mark on the neck of the flask was reached. the flask was then shaken until the solution was uniform. a 45.0-ml sample of this glucose solution was diluted to 0.500 l. how many grams of glucose are in 100. ml of the final solution?

100ml= 0,1L

Concentration of glucose = mass/ volume
Concentration=18,5/ 0,100
= 185 g/L

We take away, 0,045 L of that solution, creating another solution with it but with 0,500 L of volume

Concentration of the first solution= C1
Volume of the first solution= V1
Concentration of the second solution= C2 
Volume of the second solution= V2
C1xV1= C2xV2

185 x 0,045= C2 x 0,500
= 16,65 g/L --> this is the concentration of the new solution

The only thing left is to know the mass in 0,100 L

Concentration = mass/ volume
16,65 = mass/0,100
=1,665 grams

All the elements are arranged by melting points on the periodic table. in row they go from metals to gasses. in the row from sodium to argon, sodium is more reactive than the one on its right, magnesium.