Answer:
The correct answer is 399.8 ppm
Explanation:
A concentration in parts per million (ppm) is equal to:
Solute: Cd; Mass = 180 mg x (1 g/1000 mg) = 0.18 g
Solvent: Water ; Mass= 450.0 g x (1 kg/1000 g) = 0.45 kg
We have the following total mass of solution:
Mass of solution = Mass of solute + Mass of solvent = 0.18 g + 450 g = 450.18 g = 0.45018 kg
Finally, we divide the <u>mass of solute (in mg)</u> into the <u>mass of solution (in kg)</u> to obtain the ppm (in mg/Kg):
ppm = 180 mg/0.45018 kg = 399.8 mg/Kg = 399.8 ppm
Answer: nS2
Explanation: The valence electronic configuration of group 2a elements is "nS2",they have a complete filled "S" orbital with 2 valence electrons. e. g, Berrylium = 1s2 2S2, Calcium = 1s2 2s2 2p6 3s2 3p6 4s2
He needs to know the distance from the starting line to the finish line