Answer:
hot air rises because gases expand as they heat up.When air heats up and expands,its density also increases.The warmer,less dense air effectively floats on top of the colder, dense air below it. This creates a buoyant force that causes warmer air to rise.
cold air sinks because it is heavier as its more dense ( because of closely packed molecules) soits harder for them to move and they absorb less energy. Also, gravity pulls on it more strongly.
Hope it helps :)
Answer:
The entropy change for a real, irreversible process is equal to <u>zero.</u>
The correct option is<u> 'c'.</u>
Explanation:
<u>Lets look around all the given options -:</u>
(a) the entropy change for a theoretical reversible process with the same initial and final states , since the entropy change is equal and opposite in reversible process , thus this option in not correct.
(b) equal to the entropy change for the same process performed reversibly ONLY if the process can be reversed at all. Since , the change is same as well as opposite too . Therefore , this statement is also not true .
(c) zero. This option is true because We generate more entropy in an irreversible process. Because no heat moves into or out of the surroundings during the procedure, the entropy change of the surroundings is zero.
(d) impossible to tell. This option is invalid , thus incorrect .
<u>Hence , the correct option is 'c' that is zero.</u>
You need to use Avogadro's constant to convert from atoms of carbon to moles of carbon.
1.71*10^24 atoms C * (1 mole/6.022*10^23 atoms) = 2.84 moles of carbon
Answer:
1. 36
2. Two
Explanation:
The Lewis structure shows the valence electrons present in a compound. Usually the valence electrons are shown as dot structures around the symbol of the elements involved in the compound.
For a compound AB4 where B is more electronegative than A and A has 8 electrons in its valence shell, there will be thirty six valence electrons on the outermost shell of the molecule.
There are six electron pair domains present in the molecule, four bond pairs and two lone pairs. The molecule is in a square planar geometry.
Answer:
Explanation:
First, find the molar mass of calcium (Ca). This can be found on the Periodic Table.
Next, find the number of moles.
Avogadro's Number tells us the number of atoms in one mole.
Therefore, there are 6.023*10²³ atoms in 1 mole.
We have 6.023*10²³ atoms of calcium, so it must also be 1 mole of calcium.
Finally, find the mass. Set up a proportion using the molar mass of calcium.
Multiply. The moles (mol Ca) will cancel.
There are <u>40.08 grams </u>in 6.023*10²³ atoms of calcium.
