top-rated free essay

# Asignacion Lesson 8

By ashley618 Oct 23, 2013 550 Words
﻿
The Atomic Mass of Metallo

You may have noticed on the periodic table that the atomic mass of an element is usually not a whole number. That happens because of isotopes. An atom that is missing a neutron or has an extra neutron is called an isotope. They are still the same element; however, they are just a little different from every other atom of the same element.

Most of the carbon atoms in the universe are Carbon-12, with 6 neutrons. A small percentage of carbon atoms are Carbon-13, with 7 neutrons, and an even smaller percentage are Carbon-14 and have 8 neutrons. Carbon-13 and Carbon-14 are isotopes of carbon. Atomic mass is calculated by determining how many atoms of each isotope type are present in the universe. Since the isotopes of carbon make up only a small percentage of the carbon in the universe, the average of the masses of all carbon atoms is slightly higher than 12, so the atomic mass for carbon is actually 12.011.

Objective
Analyze the isotopes of “Metallo” and to calculate its atomic mass

Materials
sample of metallo (bag of mixed nuts, bolts, and washers)
balance

Procedures
1. Obtain a sample of the new element “Metallo.”
2. Separate the three isotopes of Metallo (nuts, washers, bolts) and measure the mass of each isotope. 3. Count the numbers of each isotope.
4. Record all data in the table.

Data Table

Erasers

Mechanical pencils(0.9)
Small candies
Totals
Total Mass (g)

45.0g
30.8g
17.9g
93.7g
Number

3
3
3
9

Average Mass (g)
45g
31g
18g
94g
Percent Abundance
1%
99%
99%
99%
Relative Abundance
1.00
0.99
0.99
0.99
Relative Mass

100
99
99
99

Analysis
1. Calculate the average mass of each isotope by dividing the total mass by the number of particles of that isotope. Record your answers on the Data Table.

2. Calculate the percent abundance of each isotope by dividing its number of particles by the total number of particles and multiplying by 100. Record your answers on the Data Table.

3. Calculate the relative abundance of each isotope by dividing the percent abundance from Step 2 by 100. Record your answers on the Data Table.

4. Calculate the relative mass of each isotope by multiplying its relative abundance from Step 3 by its average mass. Record your answers on the Data Table.

5. Calculate the average mass of all Metallo particles by adding the relative masses. This average mass is the atomic mass of Metallo.

6. Explain the difference between percent abundance and relative abundance. What is the result when you total the individual percent abundances? The individual relative abundances?

Relative abundance- a comparison between the isotopes
Percent abundance- comparing the totals.
The result is that the total of the percent abundance of the different isotopes of a given chemical element should be 100%. The result for the relative abundance is to divide by 100 and then by 1.

7. The percent abundance of each isotope tells you how many of each kind of isotope exist in every 100 particles. What does relative abundance tell you?

Relative abundance tells you ABOUT how much of a particular isotope is present in the mixture.

8. Compare the total values for Rows 3 and 6 in the Data Table. Explain why the totals differ and why the value in Row 6 best represents the atomic mass. When you compare the total values for rows 3 and 6 the totals differ , because they are both positive numbers. The value in row 6 best represents the atomic mass because it’s the relative abundance.

## Related Documents

• ###### Lesson 8 Reflection Worksheet

...﻿Name: Section: Instructions After downloading this file, type your answers right into the document (using your word processor). Once you have completed the worksheet, keep a saved copy for yourself and then upload your work to BrainHoney by clicking the “open” button at the bottom of the “reflection worksheet” page for the curre...

• ###### Human Nutrition 1 - Lesson 8

...ASSIGNMENT – LESSON 8 1. Explain in 2-3 sentences each, the role of water in the body for 5 different physiological processes. • Fluid intake and fluid excretion: There is usually a balance between intake and excretion of water. If the water balance becomes unbalanced, this can greatly affect various bodily functions such as blood...

• ###### American Government Lesson 8 Assignment

...1 Wayne Clark AC1308273 C08 American Government Lesson 8 Writing Assignment May 17, 2014 Brown v. Board of Education of Topeka Inequality in this country began when the first African slaves were brought to the North American Colony of Jamestown, Virginia, in 1619, to aid in the production of such lucrative crops as tobacco. The American Civil ...

• ###### case 8

...the company handled the initial stages of the emerging problem appropriately because the public perception of the cars and SUA became irreversible. QUESTIONS: 1. Introduce the case; 2. What do you think about any ethical issue if the managers at Toyota did not disclose the complaints it was receiving from U.S. Toyota owners or the fact that i...

• ###### Lesson Plan

...﻿Lesson 5: Live vs. Hatched Big Ideas of the Lesson Some animals are born alive. Some animals hatch from eggs. Mothers take care of their babies when they are little. Many baby animals cannot take care of themselves. Abstract This lesson focuses on identifying how animals are born. Children read a book and watch videos about life ...

• ###### Prop 8

...better! The people that oppose to it should seriously give up, get a clue and stop being so ignorant about it. There are over 30 thousand suicides a year, that’s one suicide each 17 minutes and for every completed suicide there is an estimate of about 100 to 200 attempts. Kids rejected by their parents are 8 times more likely to kill thems...

• ###### The Lesson

...﻿ Written during the height of the Civil Rights Movement, Toni Cade Bambara's short story "The Lesson" tells the story of a young African-American girl named Sylvia and the important life lesson that she learns one day while on a trip to a toy store in New York. Her neighbor, Miss Moore, brings Sylvia and a group of her friends to F.A.O. Schwa...

• ###### The Lesson

...Rupp Eng 101 October 16, 2013 The story “The Lesson,” by Toni Cade Bambara, is about a young girl named Sylvia who is accompanied by a group of her friends from her neighborhood and her elderly neighbor named Ms. Moore, who tries to teach all of them a lesson about life. “The Lesson” is a realistic story that takes place in the mid...