We live in the Milky Way Galaxy
Answer:
See explanation
Explanation:
The molecular equation shows all the compounds involved in the reaction.
The molecular equation is as follows;
2NaF(aq) + Pb(NO3)2(aq) -------> PbF2(s) + 2NaNO3(aq)
The complete ionic equation shows all the ions involved in the reaction
The complete ionic equation;
2Na^+(aq) + 2F^-(aq) + Pb^2+(aq) + 2NO3^-(aq) -------->PbF(s) + 2Na^+(aq) +2NO3^-(aq)
The net Ionic equation shows the ions that actually participated in the reaction
The net ionic equation is;
2F^-(aq) + Pb^2+(aq)--------> PbF(s)
Answer:
We could do two 1:50 dilutions and one 1:4 dilutions.
Explanation:
Hi there!
A solution that is 1000 ug/ ml (or 1000 mg / l) is 1000 ppm.
Knowing that 1 ppm = 1000 ppb, 100 ppb is 0.1 ppm.
Then, we have to dilute the stock solution (1000 ppm / 0.1 ppm) 10000 times.
We could do two 1:50 dilutions and one 1:4 dilutions (50 · 50 · 4 = 10000). Since the first dilution is 1:50, you will use the smallest quantity of the stock solution (if we use the 10.00 ml flask):
First step (1:50 dilution):
Take 0.2 ml of the stock solution using the third dispenser (20 - 200 ul), and pour it in the 10.00 ml flask. Fill with water to the mark (concentration : 1000 ppm / 50 = 20 ppm).
Step 2 (1:50 dilution):
Take 0.2 ml of the solution made in step 1 and pour it in another 10.00 ml flask. Fill with water to the mark. Concentration 20 ppm/ 50 = 0.4 ppm)
Step 3 (1:4 dilution):
Take 2.5 ml of the solution made in step 3 (using the first dispenser 1 - 5 ml) and pour it in a 10.00 ml flask. Fill with water to the mark. Concentration 0.4 ppm / 4 = 0.1 ppm = 100 ppb.
Answer:
All elements are neutral
Explanation:
The plum pudding model of the atom indicated that all elements are neutral. The model was proposed by J.J Thomson after he conducted his experiment on the gas discharge tube.
From the experiment he discovered electrons which he called cathode rays.
Therefore, he suggested the plum pudding model of the atom.
The model describes negatively charge sphere surrounded by positive charges to balance them.
Answer:
It only needs one electron.
