To solve this problem, we need to set-up algebraic expression. First, use variables to represent the number of beads.
Let: x = number of Xavier's beads
y = number of Y<span>aozhou's beads
z = number of Zara's beads
</span>It is important to note that since we have three unknowns, we should also have three independent equations. <span>Based on the given statements, we have the following three equations:
(1) x + y = 438
(2) x + z = 204
(3) y = 3z
Substitute y in terms of z in equation (1). Then multiply equation (2) with -1.
x + 3z = 438
-(x + z = 204)
-------------------
2z = 234
z = 117
From equation (3),
y = 3(117) = 351
Using equation (1),
x = 438 - 351 = 87
Thus, Xavier had 87 beads.</span>
If 20. 3 grams of an aqueous solution of iron(ii) chloride contains 2. 71 grams of iron(ii) chloride, then percentage by mass of iron(ii) chloride in the solution is 13.34%
Calculation,
Given:
mass of an aqueous solution of iron(ii) chloride = 20. 3 grams
mass of iron(ii) chloride = 2. 71 grams
The percentage by Mass is equal to percentage of mass of solute present in total mass of solution. It is also known as Mass percentage.
percentage by Mass = 100× 2. 71 grams/20. 3 grams = 13.34%
Hence, the percentage by mass of iron(ii) chloride in the solution is 13.34% .
to learn more about mass percentage
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After alpha decay (234,90) remain from it
Answer:
Physical Properties of Metals
:
Metals are lustrous, malleable, ductile, good conductors of heat and electricity. Other properties include: State: Metals are solids at room temperature with the exception of mercury, which is liquid at room temperature (Gallium is liquid on hot days).
Hope this helps! :D
<u>Answer:</u> The number of atoms in spherical gold nano particle are 
<u>Explanation:</u>
- To calculate the volume of sphere, we use the equation:
where,
r = radius of the sphere = 
(Conversion factor: 
)
Putting values in above equation, we get:
- To calculate mass of of the substance, we use the equation:
Volume of gold = 
Density of gold = 
Putting values in above equation, we get:
- To calculate the number of moles, we use the equation:
Mass of gold = 
Molar mass of gold = 196.97 g/mol
Putting values in above equation, we get:
- According to mole concept:
1 mole of an element contains 
number of atom
So, 
moles of gold will contain = 
number of atoms.
Hence, the number of atoms in spherical gold nano particle are
