The half life of cobalt-60 is 5.3 years. If a certain rock currently contains 10.0g of cabals -60 how much cobalt-60 will remain
1 answer:
T = half life of cobalt-60 = 5.3 years
λ = decay constant for cobalt-60 = ?
decay constant is given as
λ = 0.693/T
inserting the values
λ = 0.693/5.3 = 0.131
N₀ = initial amount of cobalt-60 = 10 g
t = time of decay = 21.2 years
N = final amount of cobalt-60 after time "t"
final amount of cobalt-60 after time "t" is given as
N = N₀
inserting the values
N = 10
N = 10
N = 10 x 0.0622 g
N = 0.63 g
hence
C. 0.63 g
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Answer:
the thickness of the soap film is 127.82 nm or 130 nm
Explanation:
Given the data in the question;
n = 1.33
λ = 680 nm = 680 × 10⁻⁹ m
m = 1 and β = 0
When we see the red fringe, its a point of maximum reflection
hence, for interference with a thin soap film, we say;
2 × n × d × cos( β ) = ( m - 0.5) × λ
so we substitute in our given values;
2 × 1.33 × d × cos( 0 ) = ( 1 - 0.5) × ( 680 × 10⁻⁹ )
2.66 × cos( 0 ) × d = 0.5 × ( 680 × 10⁻⁹ )
2.66 × 1 × d = 3.4 × 10⁻⁷
d = ( 3.4 × 10⁻⁷ ) / 2.66
d = 127.82 × 10⁻⁹ m
d = 127.82 nm ≈ 130 nm
Therefore, the thickness of the soap film is 127.82 nm or 130 nm