Chemistry: PLEASE HELP ME If a radioactive substance has an initial mass of 50 grams and its mass halves every 5 years, what is the number of grams remaining after 20 years?

PLEASE HELP ME If a radioactive substance has - id13185695, nadinealonzo6121

Ответ:

choudharykaran7997

11.06.2021

Chemistry

$3.125\ g$

Explanation:

Given

Initial mass $A_o=50\ g$

half-life is $T_{\frac{1}{2}}=5\ years$

At any time the left amount is given by

$A=A_o2^{-\dfrac{t}{T_{\frac{1}{2}}}}\\\\\text{Insert the values}\\\\A=50\cdot 2^{-\dfrac{20}{5}}\\\\A=50\cdot 2^{-4}\\\\A=\dfrac{50}{16}\\\\A=3.125\ g$

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Ответ:

samsavage4073

01.02.2023

Chemistry

447.63 g HClO₃

Explanation:Moles are calculated by dividing the mass of a compound by its relative formula mass.Therefore, when given the number of moles, to get the mass of the compound we multiply the number moles by the relative formula mass of the compound.Relative formula mass i given by adding the atomic masses of elements present in the compound.

In this case;

Relative formula mass of HClO₃ = 84.459 g

We are given, Moles of HClO₃ = 5.3 moles

Therefore;

Mass of HClO₃ = 5.3 moles × 84.459 g/mol

= 447.6327 g

= 447.63 g (2 d.p.)

Thus, the mass of HClO₃ in 5.3 moles is 447.63 g

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PLEASE HELP ME If a radioactive substance has an initial mass of 50 grams and its mass halves every 5 years, what is the number of
grams remaining after 20 years?

Ответ:

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