Answer:
Superscript 239 subscript 94 upper P u
(plutonium-239)
Explanation:
In alpha decay, the element subtracts 4 from its mass number and subtracts 2 from its atomic number.
So if we end with Uranium-235, which has an atomic number of 92:
235+4 = 239
92+2 = 94
Element 94 is Pu, plutonium, and its mass could very well be 239 if it's an isotope. So the answer is Superscript 239 subscript 94 upper P u.
Answer : The enthalpy change for the reaction is 1043 kJ/mol.
Explanation :
The given chemical reaction is:

As we know that:
The enthalpy change of reaction = E(bonds broken) - E(bonds formed)
![\Delta H=[(2\times B.E_{C\equiv O})+(1\times B.E_{O\equiv O})]-[2\times B.E_{C=O}]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%282%5Ctimes%20B.E_%7BC%5Cequiv%20O%7D%29%2B%281%5Ctimes%20B.E_%7BO%5Cequiv%20O%7D%29%5D-%5B2%5Ctimes%20B.E_%7BC%3DO%7D%5D)
Given:
= 1074 kJ/mol
= 499 kJ/mol
= 802 kJ/mol
Now put all the given values in the above expression, we get:
![\Delta H=[(2\times 1074kJ/mol)+(1\times 499kJ/mol)]-[2\times 802kJ/mol]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%282%5Ctimes%201074kJ%2Fmol%29%2B%281%5Ctimes%20499kJ%2Fmol%29%5D-%5B2%5Ctimes%20802kJ%2Fmol%5D)

Therefore, the enthalpy change for the reaction is 1043 kJ/mol.
Answer:
4. mutualism
5. commensalism
Explanation:
4. mutualism (they benefit off each other)
5. commensalism (the whale is unaffected)
Answer:
20.180
Explanation:
Atomic mass is the sum of the masses of the protons, neutrons, and electrons in an atom, or the averagemass, in a group of atoms
Since the question manages to include moles, pressure, volume, and temperature, then it is evident that in order to find the answer we will have to use the Ideal Gas Equation: PV = nRT (where P = pressure; V = volume; n = number of moles; R = the Universal Constant [0.082 L·atm/mol·K]; and temperature.
First, in order to work out the questions, there is a need to convert the volume to Litres and the temperature to Kelvin based on the equation:
250 mL = 0.250 L
58 °C = 331 K
Also, based on the equation P = nRT ÷ V
⇒ P = (2.48 mol)(0.082 L · atm/mol · K)(331 K) ÷ 0.250 L
⇒ P = (67.31 L · atm) ÷ 0.250 L
⇒ P = 269.25 atm
Thus the pressure exerted by the gas in the container is 269.25 atm.