Answer:
See explanation
Explanation:
The question is incomplete but i will try to give you all the necessary guide that you need in order to answer the question.
When compounds are formed, atoms exchange valency. The valency of nitrogen is three while that of the metal is two. The exchange yields M3N2.
If the compound has been specifically mentioned to be a metal, then it must be a group two element. It could be any of Mg, Ca, Sr, Ba or Ra. I did not mention Be here because most of its compounds are covalent.
This will help you to answer the complete question.
Explanation:
The given data is as follows.
Mass = 27.9 g/mol
As we know that according to Avogadro's number there are 
atom present in 1 mole. Therefore, weight of 1 atom will be as follows.
1 atoms weight = 
In a diamond cubic cell, the number of atoms are 8. So, n = 8 for diamond cubic cell.
Therefore, total weight of atoms in a unit cell will be as follows.
= 
= 
Now, we will calculate the volume of a lattice with lattice constant 'a' (cubic diamond) as follows.
= 
= 
= 
Formula to calculate density of diamond cell is as follows.
Density = 
= 
= 2918.1 
or, = 0.0029 g/cc (as 1 
)
Thus, we can conclude that density of given semiconductor in grams/cc is 0.0029 g/cc.
Answer:
Use friction
Explanation:
Friction is the force that stops something in motion. It also heats up something, creating a gravitational heat! A match striked against the lighter will create a flame, because of friction :)
The answer to this question would be: false
Autopsies are performed to the body that didn't die from a natural cause or known disease. This will include homicide or suicide. Some case that suspected to be suicide would be a homicide that was covered by the criminal. In this case, the body is examined for any unnatural or suspicious sign that might be caused by the killer. Autopsy also needed in a malpractice case.
Answer:
ΔH = -55.92 kJ
Explanation:
<u>Step 1:</u> Data given
1 mol NaOH and 1 mol HBr initially at 22.5 °C are mixed in 100g of water
After mixing the temperature rises to 83 °C
Specific heat of the solution = 4.184 J/g °C
Molar mass of NaOH = 40 G/mol
Molar mass of HBr = 80.9 g/mol
<u>Step 2: </u>The balanced equation
NaOH + HBr → Na+(aq) + Br-(aq) + H2O(l)
<u>Step 3:</u> mass of NaOH
Mass = moles * Molar mass
Mass NaOH = 1 * 40 g/mol
Mass NaOH = 40 grams
Step 4: Mass of HBr
Mass HBr = 1 mol * 80.9 g/mol
Mass HBr = 80.9 grams
Step 5: Calculate ΔH
ΔH = m*c*ΔT
ΔH= (100 + 40 + 80.9) * 4.184 * (83-22.5)
ΔH= 220.9 * 4.184 * 60.5
ΔH= 55916.86 J = 55.92 kJ
Since this is an exothermic reaction, the change in enthalpy is negative.
ΔH = -55.92 kJ
