First, calculate the mass of sodium in g with the help of molar mass and number of moles.
Number of moles = 
(1)
Molar mass of sodium =
Substitute the given value of number of moles and molar mass of sodium in formula (1)
(1)
(1)
mass of sodium in g = 
Now, according to conversion factor, 1 g = 1000 mg
So, of sodium = 
= 
of sodium
Thus, mass of sodium in mg =
Answer: ₉₈²⁵³Cf
253 is a superscript to the left of the symbol, Cf, which represents the mass number, and 98 is a subscript to the left of the same symbol, which represents the atomic number.
Explanation:
1) The alpha decay equation shows that the isotope Fm - 257, whose nucleus has 100 protons and 157 neutrons, emitted an alpha particle (a nucleus with 2 protons and 2 neutrons).
2) Therefore:
i) the mass number decreased in 4, from 257 to 257 - 4 = 253.
2) the atomic number decreased in 2, from 100 to 100 - 2 = 98.
3) Hence the formed atom has atomic number 98, which is californium, Cf, and the isotope is californium - 253.
4) The item that completes the given alpha decay reaction is:
₉₈²⁵³ Cf.
5) The complete alfpha decay reaction is:
₁₀₀²⁵⁷ Fm → ₉₈²⁵³Cf + ₂⁴He
You can verify the mass balance:
257 = 253 + 4, and
100 = 98 + 2
Answer:
The answer will be A
Explanation:
I will send a photo with it
Answer:
the last one is wrong
Explanation:
wrong : most of the mass of an atom comes from the electrons cloud
Answer: -
²²³Ra is the daughter nuclide produced when ²²⁷Th undergoes alpha decay
Explanation: -
When alpha decay occurs, the mass number of the parent decreases by 4 and the atomic number decreases by 2.
Mass number of ²²⁷Th =227
Atomic number of ²²⁷Th = 90
Mass number of daughter = 227 - 4 = 223
Atomic number of daughter = 90 - 2 = 88
88 is the atomic number of Ra Radium.
Thus the daughter is ²²³Ra
