All categories

2 years ago

lodine-131 is a radioactive isotope with a half-life of 8 days. How many grams of a 50 g sample will be left after 48 days?

Chemistry

1 answer:

RSB [31]2 years ago

4 0

Answer:

0.805 or 0.781 depending on the method used.

Explanation:

Data provided

half life ie t1/2= 8days.

No= 50g

t=48days

Nt=?

Method 1

Formula: Nt= No(1/2)^n

where n= number of half lives.

= t/t1/2 = 48/8

=6.

thus Nt= 50(1/2)^6= 0.781

Method 2

Formula: Nt= Noe^-(lambda)t

where lambda= decay constant

= ln2/ t1/2= ln2/ 8 = 0.086.

thus Nt= 50e^-(0.086×48)= 0.805.

You might be interested in

How does energy from Earth’s interior affect surface changes?

quester [9]

Answer:

Energy produced deep inside Earth heats rock in the mantle. ... As it becomes less dense, the heated rock rises toward Earth's surface. The cooler, denser rock surrounding the heated rock sinks, as Figure 5 shows. In this way, heat inside Earth moves toward the cooler crust.

Explanation:

do you like my og name

5 0

3 years ago

Read 2 more answers

How many moles are in 1.51x10^26 atoms of xenon (Xe)? Please and thank you :)!!

RoseWind [281]

<h3>Answer:</h3>

251 mol Xe

<h3>General Formulas and Concepts:</h3>

Math

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Chemistry

Atomic Structure

Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Stoichiometry

Using Dimensional Analysis

<h3>Explanation:</h3>

Step 1: Define

[Given] 1.51 × 10²⁶ atoms Xe

[Solve] moles Xe

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

[DA] Set up: $\displaystyle 1.51 \cdot 10^{26} \ atoms \ Xe(\frac{1 \ mol \ Xe}{6.022 \cdot 10^{23} \ atoms \ Xe})$
[DA] Multiply/Divide [Cancel out units]: $\displaystyle 250.747 \ mol \ Xe$