Answer:
57 mins
Explanation:
From the question given above, the following data were obtained:
Half life (t₁/₂) = 19 mins
Original amount (N₀) = 100 g
Amount remaining (N) = 12.5 g
Time (t) =?
Next, we shall determine the number of half-lives (n) that wound have elapse for 12.5 g of the sample to remain. This can be obtained as follow:
Original amount (N₀) = 100 g
Amount remaining (N) = 12.5 g
Number of half-lives (n) =?
N = 1/2ⁿ × N₀
12.5 = 1/2ⁿ × 100
Cross multiply
12.5 × 2ⁿ = 100
Divide both side by 12.5
2ⁿ = 100 /12.5
2ⁿ = 8
Express 8 index with 2 as the base
2ⁿ = 2³
n = 3
Finally, we shall determine the time taken for 100 g of the isotope to decay to 12.5 g. This can be obtained as follow:
Half life (t₁/₂) = 19 mins
Number of half-lives (n) = 3
Time (t) =?
t = n × t₁/₂
t = 3 × 19
t = 57 mins
Thus, it will take 57 mins 100 g of the isotope to decay to 12.5 g.
Ionic bonds result from the electrostatic attraction between oppositely charged ions, which form when valence electrons are transferred from one atom to another.
You can use the HWE (Hardy Weinberg Equilibrium) equations :
p + q = 1
p^2 + 2pq + q^2 = 1
If the allele combinations do not equal one after a while, evolution has occurred.
False
because carbon is very important in organic chemistry, u need to study that
Odourless, white, cubic crystals.Hygroscopic.Characteristic salty taste.Melting point = 800.8 °C.Boiling point = 1465 °C.Density = 2.165 g/cm³Solubility at 25 °C = 35.9 g/100 g water.Vapour pressure at 865 °C = 1 mm Hg.
