Who cares. Joe can solve his own problem instead of making people do it. (This was not toward you. This was supposed to be funny)
Answer:
<u><em>Decantation</em></u><em> by means of difference in relative densities.</em>
Explanation:
The specific gravity (relative density) of the gold to the soil/sand is the physical property exploited in panning gold. The particles with lower density would float whilst the heavier gold sinks lower to the bottom of the pan by gravity and is decanted off.
I hope this explanation is easy to comprehend.
Answer:
The Pauli Exclusion Principle
Explanation:
The Pauli Exclusion Principle states that, in an atom or molecule, no two electrons can have the same four electronic quantum numbers. As an orbital can contain a maximum of only two electrons, the two electrons must have opposing spins.
Answer:
0.375 grams are needed to make 25 mL solution.
Explanation:
Mass of
cuprous nitrate required to make 1 l of solution = 15 g.
1 L = 1000 mL
Mass of
cuprous nitrate required to make 1000 mL of solution = 15 g
Mass of
cuprous nitrate required to make 1 mL of solution:

Mass of
cuprous nitrate required to make 25 mL of solution:

0.375 grams are needed to make 25 mL solution.
Answer:
percent by mass = 79%
Explanation:
Data Given:
mass of solute (Na₂CO₃) = 75 g
mass of solvent ( water ) = 20 g
mass percent of solution = ?
Solution:
Formula used to find percent by mass
mass of solute / mass of solution x 100 . . . . . . (1)
first we have to find mass of solution
mass of solution = mass of solute + mass of Solvent . . . . (2)
put values in equation 2
mass of solution = 75 g + 20 g
mass of solution = 95 g
Now,
put values in equation 1
Percent by mass = mass of solute / mass of solution x 100
Percent by mass = 75 g / 95 g x 100
Percent by mass = 79 %
so,
The percent of the solution by mass = 79%
***Note:
The same work can be used for the other values too i.e. if you have 20 g of solute and 75 g solvent.