Answer:
<h3>D. </h3>
Explanation:
<h3>#I'm not sure</h3><h3>#happy learning</h3>
Explanation:
The number of protons in an atom is the atomic number.
Mass number is the number of protons plus neutrons in an atom.
Mass number = number of protons + number of neutrons
Atomic number = number of protons
Atomic number gives the symbol of the element
Number Number Atomic Mass Symbol
Protons neutrons Number Number
A 7 B 15 C
D E 26 56 F
A, number of protons = B
Mass number = protons + neutrons
15 = protons + 7
Protons = 15 - 7 = 8
Atomic number 8 is for oxygen = C
Atomic number = number of protons = D = 26
Number of neutrons ;
E = Neutrons = mass number - protons = 56 - 26 = 30
Atomic number 26 is for Iron = F
The combined gas law equation has been
.
The combined gas law has been assigned to the ideal gas. It has been stating that ideal gas are having negligible inter-molecular attraction and collision resulting in the absence of pressure and volume from the particles.
In an ideal gas the equation has been given as:

Where, <em>P </em>has been the pressure of the gas
<em>V </em>has been the volume of the gas
<em>n </em>has been the moles of the gas
<em>R </em>has been a constant
<em>T </em>has been the temperature of the gas
The combined gas law has been given as the change in the pressure, and volume for a gas. It has been given as:

For more information about combined gas law, refer to the link:
brainly.com/question/13154969