Answer:
Au
Explanation:
For the density of a face-centered cubic:

where
= molar mass of the compound
avogadro's constant
the volume of a unit cell
Given that:
Density
= 19.30 g/cm³
a = 0.408 nm
a = 
a = 
∴



Thus, the molar mass of 197.37 g/mol element is Gold (Au).
<h2>
Answer: # of neutrons = 9</h2>
<h3>
Explanation:</h3>
# of neutrons = mass number - atomic number
= 17 - 8
= 9
<h3>∴ number of neutrons in an atom of oxygen of mass number 17, is 9.</h3>
Answer:
B hope help you stay happy
Answer:
Hydrogen: -141 kJ/g
Methane: -55kJ/g
The energy released per gram of hydrogen in its combustion is higher than the energy released per gram of methane in its combustion.
Explanation:
According to the law of conservation of the energy, the sum of the heat released by the combustion and the heat absorbed by the bomb calorimeter is zero.
Qc + Qb = 0
Qc = -Qb [1]
We can calculate the heat absorbed by the bomb calorimeter using the following expression.
Q = C . ΔT
where,
C is the heat capacity
ΔT is the change in the temperature
<h3>Hydrogen</h3>
Qc = -Qb = -C . ΔT = -(11.3 kJ/°C) . (14.3°C) = -162 kJ
The heat released per gram of hydrogen is:

<h3>Methane</h3>
Qc = -Qb = -C . ΔT = -(11.3 kJ/°C) . (7.3°C) = -82 kJ
The heat released per gram of methane is:

Hey there!
Speed and velocity both:
1) Measure how fast something is moving
2) Both measured in miles per hour, meters/second, etc (rates)
However, there's a prime difference:
Different because:
1) Velocity is speed, but in a certain direction
2) Velocity is a vector
3) Velocity can be positive <em>or</em> negative, unlike speed.
I added another just in case you had a preference :)
Hope this helps!