Answer:
we can use 100g of compounds as the basis.
Explanation:
Answer:
frequency of light = 
Explanation:
we know that relation between frequency and wavelength of light is
frequency × wavelength = speed of light.
therefore frequency = 
= 
=
Answer: Y and Z. It's D.
Explanation: W represents evaporation, which is a physical change. X represents dissolving, which is also a physical change. If X and W aren't chemical changes, then Y and Z must be if half of the choices are.
Answer:
0.16 moles of Carbon
Explanation:
The balanced reaction equation:
+ 
→ 
+ 
↑
The mole ratio of Carbon to Iron is 3 : 4 (since Fe2O3 is in excess)
i.e 3 moles of C produces 4 moles of Fe.
If 1 mole of Fe - 55.8g of Fe
? moles - 11.6g of Fe
= 
= 0.208 moles
But 3 moles of C - 4 moles of Fe
? moles of C - 0.208 moles of Fe
= 
= 0.16 moles of carbon.
I hope this explanation was clear and useful.
Answer:
You determine the weighted averages if the individual isotopic masses.
Procedure:
The atomic mass of Si is the <em>weighted average </em>of the atomic masses of its isotopes.
We multiply the atomic mass of each isotope by a number representing its relative importance (i.e., its percent abundance).
The three stable isotopes of Si are Si-28 (27.98 u, 92.22 %), Si-29 (28.98 u, 4.69 %), and Si-30 (29.97 u, 3.09 %).
Set up a table for easy calculation.
0.9222 × 27.89 u = <em>x</em> u
0.0469 × 28.98 u = <em>y</em> u
0.0309 × 29.97 u = <em>z</em> u
TOTAL = (<em>x</em>+<em>y</em>+<em>z</em>) u = atomic mass of Si.
