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
Yes, that is true. in order for it to be a redox reaction, both oxidation and reduction must be occurring.
Answer:
4.90 M
Explanation:
In case of titration , the following formula can be used -
M₁V₁ = M₂V₂
where ,
M₁ = concentration of acid ,
V₁ = volume of acid ,
M₂ = concentration of base,
V₂ = volume of base .
from , the question ,
M₁ = ? M
V₁ = 125.0 mL
M₂ = 4.56 M
V₂ = 134.1 mL
Using the above formula , the molarity of acid , can be calculated as ,
M₁V₁ = M₂V₂
Substituting the respective values ,
M₁ * 125.0 mL = 4.56 M * 134.1 mL
M₁ = 4.90 M
5 is 2 I’m not sure about 4 though....
