Yes it is. Copper is the same mass and volume. Plus all pennies are made of copper
Answer:
6.24%
Explanation:
Molality by definition means a measurement of the number of moles of solute in solution with 1000 gm or 1Kg solvent. Notice the difference that Molarity is defined on the volume of solution and Molality on the mass of solvent.
So, An aqueous solution of iron(II) iodide has a concentration of 0.215 molal.
means 0.215 moles are present in 1 Kg of solvent.
The molar mass of Fe2I = 309.65 g / mole
mass of FeI2 = moles x molar mass
= 0.215 x 309.65
=66.57 gm
mass % of FeI2 = mass of FeI2 x 100 / total mass
= 66.57x 100 / (1000 +66.57)
= 6.24%
It is hard because we can't get past the crust, Our machines will burn up at the mantle and so will we. The layers go: crust, mantle, outer core, inner core.
Answer:
So the answer would be 10 moles
Explanation:
1) Start with the molecular formula for water: 
2) If there are 10 moles of water use a mole ratio to calculate the moles of oxygen it would produce.
(This question is... interesting... since they chose an element that is diatomic in free state so It could TECHNICALLY be two answers, moles of O or moles of 
)
The mole ratio is 1 moles of 
to 1 moles of O. This is because the coefficient for oxygen in water is simple 1, so the ratio is 1:1.
3) that means if 10 moles of water decompose, they decompose into 10 moles of 
and 10 moles of O.
Extra:
About what I was saying before about the question being slightly interesting:
10 moles of pure oxygen is produced but free state oxygen exists as so it could possibly be 10 OR 5! However, notice it says elements. This leads me to believe the answer is 10 (monatomic oxygen) instead of 5 (free state/diatomic oxygen).
I hope this helps!
The first one is substance 3
The second one is Oxygen, Helium, and carbon dioxide
The third one is the oil floats on top of the water
