The half-life of Th-232 is 1.405 × 10¹⁰ years
Time elapsed = 2.8 x 10⁹ years
Equation of radioactive decay:
A = A₀ = (1/2)^ t/t₁/₂
where A₀ is the initial amount, A is the amount after time t, t₁/₂ is the half file
The fraction of thorium-232 that remains in the rock after 2.8 billions years is,
A/A₀ = (1/2) ^ (2.8 x 10⁹/ 1.405 × 10¹⁰) = 0.871
Therefore, the percentage of thorium-232 in the rock that was dated at 2.8 billions year = 87.1%
Nutrients in a banana
<span>Vitamin B6 – .5 mg
Manganese – .3 mg
Vitamin C – 9 mg <span>
Potassium – 450 mg </span></span>
<span>Dietary Fiber – 3g
Protein – 1 g
Magnesium – 34 mg
Folate – 25.0 mcg </span>
<span>Riboflavin – .1 mg
Niacin – .8 mg
Vitamin A – 81
IU Iron – .3 mg</span>
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The phase change in which a substance changes from a gas directly to a solid is nominated "deposition".
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