lalamonique310 lalamonique310

02-01-2018
Chemistry

contestada

the half-life of Zn-71 is 2.4 minutes. if one had 100.0 grams at the beginning, how many grams would be left after 7.2 minutes has elapsed?

Respuesta :

JoannaBlackwelder JoannaBlackwelder

02-01-2018

7.2 minutes is exactly 3 half-lives (3*2.4 = 7.2). For each half-life, we divide the amount we have by 2.
1st half-life = 100.0/2 = 50.00 g
2nd half-life = 50.00/2 = 25.00 g
3rd half-life = 25.00/2 = 12.50 g
So we have 12.30 g after 7.2 minutes.

Answer Link

Otras preguntas

What is the distance from the center of the hexagon to the midpoint of the side?

Help! Urgent. Will give thanks and branliest. For my English project I need to make a claim about a book I read. My claim is that Harry Potter and Percy Jackson

Edgar has a birdbath that holds 2 gallons of water. he only wants to fill it 3/4 full. how much water, in gallons, should edgar put in the birdbath?

What is the mechanical advantage of the lever?

Calculate and simplify: 18/20 + 4/8 =

name the vertices of the image reflected in the x-axis

Which answer shows a correct order to solve this story problem? Maurine had to pay $2.52 tax on her purchases. She bought 3 books for $12.99 each, 2 pens for

I need help with this I don't understand

Find two numbers with a sum of 20 and a difference of 14

Which of the following tells what you have just done? Estoy bailando. Hace tres días que bailo. Hace tres días que bailé. Acabo de bailar.