Atomic mass Boron ( B ) = 10.811 u.m.a
10.811 g -------------- 6.02x10²³ atoms
5.40 g ----------------- ?? atoms
5.40 x ( 6.02x10²³) / 10.811 =
3.0069x10²³ atoms
Answer:
Because there is trapped air inside the cube of ice
Explanation:
when water freezes it has water molecules and air molecules and as it freezes they move slower and slower until it freezes and they become stuck
Answer:
Hi there!
Your answer is:
A.
Explanation:
When frozen, water turns from a liquid to a solid! An example of this is a glass of water. You fill the glass with liquid tap water, and then put ice cubes in it. The ice cubes are solid and the tap water is liquid!
I hope this helps!
Answer:
insoluble simply means something that cannot be dissolved in water (:
These problems are a bit interesting. :)
First let's write the molecular formula for ammonium carbonate.
NH4CO3 (Note! The 4 and 3 are subscripts, and not coefficients)
17.6 gNH4CO3
Now to convert to mol of one of our substances we take the percent composition of that particular part of the molecule and multiply it by our starting mass. This is what it looks like using dimensional analyse.
17.6 gNH4CO3 * (Molar Mass of NH4 / Molar Mass of NH4CO3)
Grab a periodic table (or look one up) and find the molar masses for these molecules! Well. In this case I'll do it for you. (Note: I round the molar masses off to two decimal places)
NH4 = 14.01 + 4*1.01 = 18.05 g/mol
NH4CO3 = 14.01 + 4*1.01 + 12.01 + 3*16.00 = 78.06 g/mol
17.6 gNH4CO3 * (18.05 molNH4 / 78.06 molNH4CO3)
= 4.07 gNH4
Now just take the molar mass we found to convert that amount into moles!
4.07 gNH4 * (1 molNH4 / 18.05 gNH4) = 0.225 molNH4
