Answer:
Dark matter makes up 85% of the mass of the universe. Dark matter is not directly observable because it doesn't interact with any electromagnetic wave. In the development of the universe, without dark matter, the universe will not function, move or rotate as it does now (this speculation led to the quest to find the anomaly of mass and energy in the known universe, eventually leading to the idealization of dark matter) and will not have enough gravitational force to hold it together. After the big bang,<em> the presence of dark matter and energy ensured that the newly formed universe didn't just float away, rather, it provided enough gravitational force to hold the universe while still allowing it to expand sufficiently</em>.
The development of the universe would have been different without the universe in the sense that the young universe won't have enough mass to hold it together, and the universe would have simply floated apart. The behavior of the universe would have been different from what we observe now, and some physical laws that applies now will not apply to the universe.
Answer:
The difference in mass between 3.01×10^24 atoms of gold and a gold bar with the dimensions 6.00 cm X 4.25 cm X 2.00 cm is :
<u>Difference</u> <u>in mass</u> =<u> 985.32 - 984.5 = 0.82 g</u>
Explanation:
<u>Part I :</u>

n = 4.9983
n = 4.99 moles
(Note : You can also take n = 5 mole )
Molar mass of gold = 196.96 g/mole
This means, 1 mole of gold(Au) contain = 196.96 grams
So, 4.99 moles of gold contain =
g
4.99 moles of gold contain = 984.8 g
Mass of
atoms of gold = 984.5 g
<u>Part II :</u>
Density of Gold = 
Volume of the cuboid = 
Volume of the gold bar =
Volume of the gold bar = 51
Using formula,

Mass = 985.32 g
So, A gold bar with the dimensions 6.00 cm X 4.25 cm X 2.00 cm has mass of <u>985.32 g</u>
<u>Difference</u> <u>in mass</u> =<u> 985.32 - 984.5 = 0.82 g</u>
I believe it is “Conduction” im not 100% sure tho, I haven’t done this since the 7th grade.