Uranium–232 has a half–life of 68.9 years. a sample from 206.7 years ago contains 1.40 g of uranium–232. how much uranium was originally present?

The initial amount of Uranium-232 present is 11.3 grams.

Explanation:

All the radioactive reactions follows first order kinetics.

The equation used to calculate half life for first order kinetics:

We are given:

Putting values in above equation, we get:

Rate law expression for first order kinetics is given by the equation:

where,

k = rate constant =

t = time taken for decay process = 206.7 yrs

= initial amount of the reactant = ?

[A] = amount left after decay process = 1.40 g

Putting values in above equation, we get:

Hence, the initial amount of Uranium-232 present is 11.3 grams.

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explanation:

"hydrogen bonding is the attraction of h atoms in the water molecule (slight + charge) to o atoms in a neighboring water molecule (slight - charge); it is a weak interatomic force. but it is still strong enough to the water molecules "stick" together."