Answer:
2500kg/m3
Explanation:
Mass=20g= 20×10^-3kg
Volume=8x10^-6m3
<h2>Now we know that Density = mass\volume</h2>
D= 20×10^-3/8×10^-6
=2500kg/m3
Answer : The final temperature of the copper is, 
Solution :
Formula used :

where,
Q = heat gained = 299 cal
m = mass of copper = 52 g
c = specific heat of copper =
= final temperature = ?
= initial temperature = 
Now put all the given values in the above formula, we get the final temperature of copper.


Therefore, the final temperature of the copper is, 
When a molecule is broken down into its constituent atoms, these atoms do not have the same properties as the molecule.
We can use an everyday molecule, such as water, H20, to show this property. Water is a liquid with unique properties that stem from its hydrogen bonding. On the other hand, its constituent atoms, hydrogen and oxygen, are not liquids, and have very different properties. Oxygen and hydrogen are both gases; hydrogen is dangerous and very flammable, while we breathe in oxygen throughout our lives. This example illustrates how the atoms that make up a molecule usually have different properties than the completed molecule.
Hope this helps!
Answer:
2 mol H
Explanation:
For every 2 mol of NaOH, we're reacting 2 mol of H2O. In order to figure out how many mol of H are needed, it needs to be set up stochiometrically. Starting off with the given value, 1 mol of NaOH, we can then make a mol to mol ratio. For 2 mol of NaOH, we have 2 mol of H2O. For every 2 mol of H2O, we have 4 mol of H (this is because we are multiplying the coefficient by the subscript: 2 × 2). Now, we can solve for our answer.
1 mol NaOH × (2 mol H₂O / 2 mol NaOH) × (4 mol H / 2 mol H₂O)
= 2 mol H
Thus, we get 2 mol of H are needed to completely react 1 mol of NaOH.
The answer is B. Because reactions are what goes in. Products are what comes out