The question didn't make sense, could you add more to it?
Answer:
14.99 hours
Step-by-step explanation:
The formula for half-life is given as,
R/R' = 2ᵃ/ᵇ...................... Equation 1
Where R= Original mass of sodium-24, R' = mass of Sodium-24 after disintegration, a = Total time taken for sodium-24 to disintegrate, b = half-life of sodiun-24.
Given: R = 1 kg, R' = 0.0156 kg, a = 90 hours
Substitute into equation 1 and solve for b
1/(0.0156) = 2⁹⁰/ᵇ
Taking the log of both side
log[1/(0.0156)] = log(2⁹⁰/ᵇ)
log[1/(0.0156)] = 90/b(log2)
90/b = log[1/(0.0156)]/log2
90/b = 6.0023
b = 90/6.0023
b = 14.99 hours
b = 14.99 hours.
Hence the half-life of Sodium-24 is 14.99 hours
What is 0.00340.78 correct to 3 significant figures?
a significant fugure is when the number lean solething ,so its can anyone except 0
so if we are reducing 0.00340.78 to 3 significant number
first we have to look for the significant nulber ,which are 3,4,7,8
so the answer can be 0.0034.7
hopefully this helps
Answer:
Third option is correct!
Step-by-step explanation:
x+19<28
or, x<9
so
x = {3,4,5,6}
