Answer:
24
Explanation:
The number of protons in the atom of the neutral element will also be 24.
Protons are the positively charged particles in an atom.
Electrons are the negatively charged particles
Neutrons do not carry any charges at all
Now, in a neutral atom, the charge is balanced and the number of protons and electrons are the same in the atom.
So, since we have been given that the atom has 24 electrons, the number of protons will be 24.
The valence electron ring is full. The ring has 8 electrons already.
Answer:
Final temperature: 659.8ºC
Expansion work: 3*75=225 kJ
Internal energy change: 275 kJ
Explanation:
First, considering both initial and final states, write the energy balance:
Q is the only variable known. To determine the work, it is possible to consider the reversible process; the work done on a expansion reversible process may be calculated as:
The pressure is constant, so:
(There is a multiplication by 100 due to the conversion of bar to kPa)
So, the internal energy change may be calculated from the energy balance (don't forget to multiply by the mass):
On the other hand, due to the low pressure the ideal gas law may be appropriate. The ideal gas law is written for both states:
Subtracting the first from the second:

Isolating
:

Assuming that it is water steam, n=0.1666 kmol

ºC
4li + o2 ----> 2li2o
8 x
cross multiply 8x2 ÷ 4x
x=4
the answer is 4