Chemistry, 24.07.2019 14:00 janeou17xn

Iridium-192 is one radioisotope used in brachytherapy in which a radioactive source is placed inside a patient's body to treat cancer. brachytherapy allows the use of a higher than normal dose to be placed near the tumor while lowering the risk of damage to healthy tissue. iridium-192 is often used in the head or breast. if a sample of iridium-192 is initially 3.25g and 1.21g remains after 105 days, estimate the half-life of the radioisotope.

Answers: 1

Show answers

Answers

Answer is: the half-life of the radioisotope is 74 days.
m₀ = 3.25 g.
m₁ = 1.21 g.
t = 105 d.
ln(m₀/m₁) = k· t.
ln(3.25/1.21) = k·105 d.
ln(2.685) = 105·k.
0.98 = 105k.
k = 0.0094.
t1/2 = ln2 / k.
t1/2 = 0.693 / 0.0094.
t1/2 = 73.72 days.

Answer from: dijaflame67

The half-life of the radioisotope : 73.68 days

Further explanation

The core reaction is a reaction that causes changes in the core structure.

In the core reaction, the number of atomic numbers and mass numbers of the reactants is the same as the atomic number and mass number of the product

Radioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles, among others

alpha α particles ₂He⁴ beta β ₋₁e⁰ particles gamma particles γ positron particles ₁e⁰

General formulas used in decay:

$\large {\boxed {Nt=No(\frac {1} {2})^{\frac {T} {t1 / 2}}}}$

T = duration of decay

t 1/2 = half-life

No = the number of initial radioactive atoms

Nt = the number of radioactive atoms left after decaying during T time

A sample of iridium-192 is initially 3.25 g and 1.21 g remains after 105 days, estimate the half-life of the radioisotope

So :

No = 3.25 g

Nt = 1.21 g

T = 105 days

We input this to equation to find half life ( $\displaystyle t\frac{1}{2}$

$\displaystyle Nt=No(\frac {1} {2})^{\frac {T} {t\frac{1}{2}}$

$\displaystyle 1.21=3.25(\frac {1} {2})^{\frac {105} {t\frac{1}{2}}$

$\displaystyle 0.372=(\frac{1}{2})^{\frac{105}{t\frac{1}{2} }$

$\displaystyle log~0.372=\frac{105}{t\frac{1}{2} }.log~0.5\\\\-0.429=\frac{105}{t\frac{1}{2} }.-0.301\\\\1.425=\frac{105}{t\frac{1}{2} }\\\\t\frac{1}{2}=\boxed{\bold{73.68~days}}$

Learn more

exponential decay

link

nuclear decay reaction

link

Plutonium − 239

link

Keywords: the half-life, decay reaction, iridium-192

Iridium-192 is one radioisotope used in brachytherapy in which a radioactive source is placed inside

Answer from: Quest

Any photo? or something

Answer from: Quest

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

Another question on Chemistry

Chemistry, 21.06.2019 18:30

Covalent network solids typically have melting points and boiling points. the chemical formula of a network solid indicates in the molecule.

Answers: 3

Answer

Chemistry, 22.06.2019 15:30

All motion is caused by force? true or false

Answers: 1

Answer

Chemistry, 22.06.2019 20:10

Insoluble sulfide compounds are generally black in color. which of the following combinations could yield a black precipitate? check all that apply. na2s(aq)+kcl(aq) li2s(aq)+pb(no3)2(aq) pb(clo3)2(aq)+nano3(aq) agno3(aq)+kcl(aq) k2s(aq)+sn(no3)4(aq)

Answers: 1

Answer

Chemistry, 22.06.2019 21:30

How many oxygen atoms are there in 3.15 moles of hcl manganese (iv) oxide, mno2

Answers: 2

Answer

You know the right answer?

Iridium-192 is one radioisotope used in brachytherapy in which a radioactive source is placed inside...

Questions