Protons, Neutrons, and Electrons—How Atoms Differ1+LESSON+11.pdfProtons, Neutrons, and...
Transcript of Protons, Neutrons, and Electrons—How Atoms Differ1+LESSON+11.pdfProtons, Neutrons, and...
7th Grade Science
Isotopes and ions
UNIT 1 LESSON 11
Do Now
Name_____________________________________ Date:_____________________________________
26
Fe
Iron
55.845
Directions: Label the period table entry and fill in the missing blanks.
Atomic # = ______
Atomic Mass = _________
Mass # = _________
# of Protons = ________
# of Neutrons = ________
# of Electrons = ________
Understanding the Atom 33
Cop
yrig
ht ©
Gle
ncoe
/McG
raw
-Hill
, a d
ivis
ion
of T
he M
cGra
w-H
ill C
ompa
nies
, Inc
.
Name Date Class
LESSON 2Content Practice B
Protons, Neutrons, and Electrons—How Atoms DifferDirections: Complete the chart with the correct terms from the word bank in the space provided. Some terms may be used more than once.
e- electron cloud around the nucleus n nucleus p
0 1/1,840 1- 1 1+
Properties of Protons, Neutrons, and Electrons
Electron Proton Neutron
Symbol 1. 5. 9.
Charge 2. 6. 10.
Location 3. 7. 11.
Relative Mass
4. 8. 12.
Directions: Answer each question on the lines provided.
13. What makes an atom of one element different from an atom of another element?
14. An element has 6 protons and 6 neutrons. What is its atomic number? What is its mass number?
15. What happens to a neutron atom if it gains or loses electrons?
C322_027_033_CRF_L2_892506.indd 33C322_027_033_CRF_L2_892506.indd 33 2/24/10 4:59:21 PM2/24/10 4:59:21 PM
1/1,840 1
e-
nucleus
7th Grade Science
Isotopes
UNIT 1 LESSON 11
Notes
Name_____________________________________ Date:_____________________________________
Aim: SWBAT understand how a neutral atom changes when it’s numbers of protons, electrons, or neutrons change.
92 Understanding the Atom
Lesson 2
Skim Lesson 2 in your book. Read the headings and look at the photos and illustrations. Identify three things you want to learn more about as you read the lesson. Record your ideasin your Science Journal.
Protons, Neutrons, and Electrons—How Atoms Differ
Copyright © Glencoe/McGraw-Hill, a division of The M
cGraw-Hill Companies, Inc.
Distinguish parts of the atom.
Part Electron Proton Neutron
Symbol
Charge
Location
Relative Mass
Relate details about atomic number.
Atomic Number
determines equals , and also equals
in neutral atoms
Differentiate numbers of protons and neutrons in different isotopes of the same element.
Numbers of protons:
Numbers of neutrons:Isotopes of
the Same Element
Contrast the numbers of particles represented by an element’s mass number and atomic number.
Atomic Number Mass Number
The Parts of the Atom I found this on page .
Neutrons and IsotopesI found this on page .
Different Elements—Different Numbers of ProtonsI found this on page .
I found this on page .
1
C322_006_008_L2_SN_889435.indd Page 6 2/18/10 10:13:44 AM u-s083C322_006_008_L2_SN_889435.indd Page 6 2/18/10 10:13:44 AM u-s083 /Volumes/101/GO00261/MSS_Ntbk_Ancillaries%0/MSS12-SN_12/Application_Files.../Volumes/101/GO00261/MSS_Ntbk_Ancillaries%0/MSS12-SN_12/Application_Files.
Different Elements – Different Numbers of Protons
What are the atomic numbers of carbon, nitrogen and oxygen? _________________________________ __________________________________________________________________________________________ Explain the difference between an oxygen atom and a carbon atom. _____________________________ __________________________________________________________________________________________
92 Understanding the Atom
Lesson 2
Skim Lesson 2 in your book. Read the headings and look at the photos and illustrations. Identify three things you want to learn more about as you read the lesson. Record your ideasin your Science Journal.
Protons, Neutrons, and Electrons—How Atoms Differ
Copyright ©
Glencoe/M
cGraw
-Hill, a division of T
he McG
raw-H
ill Com
panies, Inc.
Distinguish parts of the atom.
Part Electron Proton Neutron
Symbol
Charge
Location
Relative Mass
Relate details about atomic number.
Atomic Number
determines equals , and also equals
in neutral atoms
Differentiate numbers of protons and neutrons in different isotopes of the same element.
Numbers of protons:
Numbers of neutrons:Isotopes of
the Same Element
Contrast the numbers of particles represented by an element’s mass number and atomic number.
Atomic Number Mass Number
The Parts of the Atom I found this on page .
Neutrons and IsotopesI found this on page .
Different Elements—Different Numbers of ProtonsI found this on page .
I found this on page .
1
C322_006_008_L2_SN_889435.indd Page 6 2/18/10 10:13:44 AM u-s083C322_006_008_L2_SN_889435.indd Page 6 2/18/10 10:13:44 AM u-s083 /Volumes/101/GO00261/MSS_Ntbk_Ancillaries%0/MSS12-SN_12/Application_Files.../Volumes/101/GO00261/MSS_Ntbk_Ancillaries%0/MSS12-SN_12/Application_Files.
Neutrons and Isotopes • Isotopes are atoms of the same element that have different
numbers of neutrons. Most elements have several isotopes.
How do the carbon isotopes differ? _____________________________________________________________________________ _____________________________________________________________________________
Atomic Number vs. Mass Number
92 Understanding the Atom
Lesson 2
Skim Lesson 2 in your book. Read the headings and look at the photos and illustrations. Identify three things you want to learn more about as you read the lesson. Record your ideasin your Science Journal.
Protons, Neutrons, and Electrons—How Atoms Differ
Copyright ©
Glencoe/M
cGraw
-Hill, a division of T
he McG
raw-H
ill Com
panies, Inc.
Distinguish parts of the atom.
Part Electron Proton Neutron
Symbol
Charge
Location
Relative Mass
Relate details about atomic number.
Atomic Number
determines equals , and also equals
in neutral atoms
Differentiate numbers of protons and neutrons in different isotopes of the same element.
Numbers of protons:
Numbers of neutrons:Isotopes of
the Same Element
Contrast the numbers of particles represented by an element’s mass number and atomic number.
Atomic Number Mass Number
The Parts of the Atom I found this on page .
Neutrons and IsotopesI found this on page .
Different Elements—Different Numbers of ProtonsI found this on page .
I found this on page .
1
C322_006_008_L2_SN_889435.indd Page 6 2/18/10 10:13:44 AM u-s083C322_006_008_L2_SN_889435.indd Page 6 2/18/10 10:13:44 AM u-s083 /Volumes/101/GO00261/MSS_Ntbk_Ancillaries%0/MSS12-SN_12/Application_Files.../Volumes/101/GO00261/MSS_Ntbk_Ancillaries%0/MSS12-SN_12/Application_Files.
Average Atomic Mass
Define average atomic mass. _________________________________________________________ ________________________________________________________ ________________________________________________________ ________________________________________________________
How is the average atomic mass calculated? The abundance of each isotope is changed to decimal form. The mass of each isotope is multiplied by it’s corresponding decimal percentage. All the values are added together to determine the average atomic mass
0.989 x 12 = 11.868 0.0101 x 13= + 0.143 12.011
Independent Practice
Understanding the Atom 29
Co
pyri
gh
t ©
Gle
nco
e/M
cGra
w-H
ill,
a d
ivis
ion
of
Th
e M
cGra
w-H
ill
Co
mp
anie
s, I
nc.
Name Date Class
Lesson Outline LESSON 2
Protons, Neutrons, and Electrons—How Atoms DifferA. The Parts of the Atom
1. Protons and have about the
same .
2. have much less mass than the other two particles in an atom.
3. Most of the mass of an atom is in the .
B. Different Elements—Different Numbers of Protons
1. The number of protons in an atom of an element is the
element’s .
2. Different elements contain different numbers of .
3. In a neutral atom, the number of equals the number of
protons because the number of charges must equal the
number of positive charges.
C. Neutrons and Isotopes
1. are atoms of the same element that have different
numbers of .
2. The total number of and neutrons in an atom is the
of the atom.
3. The of an element is the average mass of the
element’s .
a. The average atomic mass is according to the abundance of each isotope.
b. Weighted means that the average atomic mass is based on the
of each atom in a sample and the number of atoms
of that that are present.
D. Radioactivity
1. first noticed that some elements spontaneously give
off .
C322_027_033_CRF_L2_892506.indd 29C322_027_033_CRF_L2_892506.indd 29 2/24/10 4:59:15 PM2/24/10 4:59:15 PM
ATOMIC STRUCTURE WORKSHEET Fill in the blanks. Use your periodic table. Round up atomic mass if necessary.
1. Atomic Number for Copper _______________
2. Number of electrons for Sulfur __________________
3. Number of protons for Hydrogen _________________
4. Atomic mass for Oxygen ____________________
5. Number of electrons for Phosphorous _____________________
6. Atomic number for Helium _______________________
7. Number of protons for Lithium _____________________
8. Atomic mass for K _________________________
9. Number of protons for Be _________________________
10.Number of neutrons for Ni ________________________
11.Atomic number for C _______________________
12.Number of protons for Fe ___________________
13.Atomic mass for Cl ___________________
14.Atomic number for Na ________________________
15.Number of electrons for N _________________________
16.This element has 9 protons ___________________
17.This element has 80 electrons ___________________
18.This element has an atomic number of 46 _______________________
19.This element has an atomic number of 18 _______________________
20.This element has 5 electrons _______________________
21. This element has 12 protons _______________________
Copyright ©
Glencoe/M
cGraw
-Hill, a division of T
he McG
raw-H
ill Com
panies, Inc.
Alpha Decay An alpha particle is made of two protons and two neutrons. When an atom releases an alpha particle, its atomic number decreases by two. Uranium-238 decays to thorium-234 through the process of alpha decay.
Beta Decay In beta decay, a neutron in an atom changes into a proton and a high-energy electron called a beta particle. The new proton becomes part of the nucleus. The beta particle is released. In beta decay, the atomic number of an atom increases by one because it has gained a proton.
Gamma Decay Gamma rays do not contain particles, but they do contain a lot of energy. In fact, gamma rays can pass through thin sheets of lead! Because gamma rays do not contain particles, the release of gamma rays does not change one element into another element.
Uses of Radioactive IsotopesThe energy released by radioactive decay can be harmful
as well as beneficial to humans. Too much radiation can damage or destroy living cells, making them unable to function properly. Some organisms contain cells, such as cancer cells, that are harmful to the organism. Radiation therapy can be beneficial to humans by destroying these harmful cells.
Ions—Gaining or Losing ElectronsWhat happens to a neutral atom if it gains or loses
electrons? Recall that a neutral atom has no overall charge. This is because it contains equal numbers of positively charged protons and negatively charged electrons. When electrons are added to or removed from an atom, that atom becomes an ion. An ion is an atom that is no longer neutral because it has gained or lost electrons. An ion can be positively or negatively charged, depending on whether it has lost or gained electrons.
Positive IonsWhen a neutral atom loses one or more electrons, it has
more protons than electrons. As a result, it has a positive charge. An atom with a positive charge is called a positive ion. A superscript plus sign (+) following the element’s symbol represents a positive ion. For example, the top half of the figure on the next page shows how sodium (Na) becomes a positive sodium ion (Na+).
Key Concept Check10. Describe What happens during radioactive decay?
Reading Check12. Differentiate How is an ion different from a neutral atom?
11. Apply Why do people who work with radioactive materials wear special protective clothing?
172 Understanding the Atom Reading Essentials
C322_011_018_RE_L2_889408.indd 16C322_011_018_RE_L2_889408.indd 16 2/25/10 3:18:13 PM2/25/10 3:18:13 PM
Cop
yrig
ht ©
Gle
ncoe
/McG
raw
-Hill
, a d
ivis
ion
of T
he M
cGra
w-H
ill C
ompa
nies
, Inc
.
Negative IonsWhen a neutral atom gains one or more electrons, it has
more electrons than protons. As a result, the atom has a negative charge. An atom with a negative charge is called a negative ion. A superscript negative sign (-) following the element’s symbol represents a negative ion. The bottom half of the figure above shows how fluorine (F) becomes a fluorine ion (F-).
Key Concept Check 14. Explain How does a neutral atom change when its number of protons, electrons, or neutrons changes?
Visual Check13. Evaluate Why does a fluorine ion have a negative charge?
Formation of Positive and Negative Ions
+ + + + + + + + +- - - - - - - - -
+ + + + + + + +- - - - - - - -
+ + + + + + + + +- - - - - - - - -
+-
+-
+ + + + + + + + +- - - - - - - - -
+-
+
+- -
11 protons
10 electrons
9 protons
10 electrons
9 protons
9 electrons
11 protons
11 electrons
Sodium atom (Na)
Fluorine atom (F)
Sodium ion (Na+)
Fluorine ion (F–)
Reading Essentials Understanding the Atom 173
C322_011_018_RE_L2_889408.indd 17C322_011_018_RE_L2_889408.indd 17 2/25/10 3:18:20 PM2/25/10 3:18:20 PM
Cop
yrig
ht ©
Gle
ncoe
/McG
raw
-Hill
, a d
ivis
ion
of T
he M
cGra
w-H
ill C
ompa
nies
, Inc
.
Negative IonsWhen a neutral atom gains one or more electrons, it has
more electrons than protons. As a result, the atom has a negative charge. An atom with a negative charge is called a negative ion. A superscript negative sign (-) following the element’s symbol represents a negative ion. The bottom half of the figure above shows how fluorine (F) becomes a fluorine ion (F-).
Key Concept Check 14. Explain How does a neutral atom change when its number of protons, electrons, or neutrons changes?
Visual Check13. Evaluate Why does a fluorine ion have a negative charge?
Formation of Positive and Negative Ions
+ + + + + + + + +- - - - - - - - -
+ + + + + + + +- - - - - - - -
+ + + + + + + + +- - - - - - - - -
+-
+-
+ + + + + + + + +- - - - - - - - -
+-
+
+- -
11 protons
10 electrons
9 protons
10 electrons
9 protons
9 electrons
11 protons
11 electrons
Sodium atom (Na)
Fluorine atom (F)
Sodium ion (Na+)
Fluorine ion (F–)
Reading Essentials Understanding the Atom 173
C322_011_018_RE_L2_889408.indd 17C322_011_018_RE_L2_889408.indd 17 2/25/10 3:18:20 PM2/25/10 3:18:20 PM
Directions: Answer the following questions in complete sentences
1. How is an ion different from a neutral atom? _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________
2. Why does a fluorine ion have a negative charge? ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________
3. How does a neutral atom change when its number of protons, electrons and neutrons changes?
_______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________
7th Grade Science
Atomic Mass and Atomic Number
UNIT 1
LESSON 11
Exit Ticket
Name_____________________________________ Date:_____________________________________
Directions: On each line write the term from the word bank that correctly completes each sentence. Not all terms are used!
1. The ____________________________ is a weighted average that reflects the abundance of different isotopes.
2. The ______________________________ is determined by adding the number of protons and neutrons in an atom.
3. __________________________ are atoms of the same element that have different numbers of neutrons.
4. An element’s ____________________________ and the number of protons in the nucleus of its atoms are always the same.
56 Understanding the Atom
Copyrig
ht ©
Glen
coe/M
cGraw
-Hill, a d
ivisio
n o
f The M
cGraw
-Hill C
om
pan
ies, Inc.
Name Date Class
Chapter Test B continued
CompletionDirections: One each line, write the term from the word bank that correctly completes each sentence. Not all terms are used.
atomic number average atomic mass elements
ions isotopes mass number
neutrons nucleus protons
7. The is a weighted average that reflects the abundance of different isotopes.
8. The is determined by adding the number of protons and neutrons in an atom.
9. are atoms of the same element that have different numbers of neutrons.
10. always have a positive or negative charge.
11. An element’s and the number of protons in the nucleus of its atoms are always the same.
Interpreting a Table Directions: Complete this table by choosing terms from the word bank and writing them in the correct spaces. Not all terms are used.
1 high-energy electron 1 proton 2 protons and 2 neutrons
decreases by 2 decreases by 1 energy
increases by 1 increases by 2 none
Type of Decay
What Is Released?
Released Material Consists of
New Element Formed?
Change in Atomic Number
alpha decay
alpha particle
12. yes 13.
beta decay
beta particle
14. yes 15.
gamma decay
gamma ray 16. no 17.
C322_052_060_CRF_ChTests_892506.56 56C322_052_060_CRF_ChTests_892506.56 56 2/24/10 5:51:28 PM2/24/10 5:51:28 PM