<h3>Answer:</h3>
Curium-247 <em>i.e.</em> ²⁴⁷₉₆Cm
<h3>Explanation:</h3>
Alpha decay is given by following general equation,
ᵃₓA → ⁴₂He + ᵃ⁻⁴ₓ₋₂B
Where;
A = Parent Isotope
B = Daughter Isotope
ᵃ = Mass Number
ₓ = Atomic Number
Californium-251 is the parent isotope in our case and it has 98 protons (atomic number) and is given as,
²⁵¹₉₈Cf
The alpha decay reaction of Californium-251 will be as,
²⁵¹₉₈Cf → ⁴₂He + ²⁴⁷₉₆B
The symbol for B with atomic number 96 was found to be the atom of Curium (Cm) by inspecting periodic table. Hence, the final equation is as follow,
²⁵¹₉₈Cf → ⁴₂He + ²⁴⁷₉₆Cm
Charles law states that volume of gas is directly proportional to temperature at constant pressure
V/T = k
where V - volume , T - temperature and k - constant

where parameters for the first instance are on the left side and parameters for the second instance are on the right side of the equation
in the question it states that the temperature has been increased from 278 K to 231 K but it should actually be temperature is decreased from 278 K to 308 K
substituting the values in the equation

V = 462 cm³
the answer should be D. 462 cm³
Answer:
D
Explanation:
Because the number of protons is the same as the atomic number, we know what the number of protons has to be 26. The mass number, 55, is the same as the number of protons plus neutrons. Lastly, because there is no charge on this atom, the number of electrons would have to be the same as the number of protons, which is 26.
Particles in a gas are far apart compared to a solid or liquid, allowing it not to have a definitive shape or volume. This also means that gases can fill any container and be easily compressed.