Problems 

Isotope

N

Protons

At. Mass

At. #

e-1

72

53

48

110

Fluorine-18

Calcium-

21

1

2

*All isotopes are neutral.

ANSWERS BELOW

Isotope

N

Protons

At. Mass

At. #

e-1

Iodine-125

72

53

125

53

53

Cadmium-110

62

48

110

48

48

Fluorine-18

9

9

18

9

9

Calcium-41

21

20

41

20

20

Helium-3

1

2

3

2

2

Isotope

N

Protons

At. Mass

At. #

Symbol

32

30

38

80

Nitrogen-15

Aluminum-

15

6

5

All are neutral!

ANSWERS BELOW

Isotope

N

Protons

At. Mass

At. #

Symbol

Zinc-62

32

30

62

30

6230Zn

Strontium-80

42

38

80

38

8038Sr

Nitrogen-15

8

7

15

7

157N

Aluminum-28

15

13

28

13

2813Al

Boron-11

6

5

11

5

115B

Isotope

N

Protons

Symbol

e-1

At.Mass

8035Br-1

5

4

2

Neon-22

Phosphide-  ion

15

7

14

ANSWERS BELOW

Isotope

N

Protons

Symbol

e-1

At.Mass

Bromide-80 ion

45

35

8035Br1-

36

80

Beryllium-9 ion

5

4

94Be2+

2

9

Neon-22

12

10

2210Ne

10

22

Phosphide-30 ion

15

15

3015P3-

18

30

Nitrogen-14

7

7

147N

7

14

Honors Chem.

Symbol

Isotope

e-

At #

N

Mass

36

17 Cl-1

14

6   C

Carbon-

6

Neon-24

  S-2

18

34

ANSWERS BELOW

Symbol

Isotope

e-

At #

N

Mass

36

17  Cl-1

Chloride-36 ion

18

17

19

36

14

6   C

Carbon-14

6

6

8

14

24

10  Ne

Neon-24

10

10

14

24

34

16  S-2

Sulfide-34 ion

18

16

18

34

Isotope

e-

N

Mass

Symbol

P

56

26 Fe

15

33

15

54

76

129

Chromium-46

ANSWERS BELOW

Isotope

e-

N

Mass

Symbol

P

Iron 56

26

30

56

56

26 Fe

26

Phosporous-33

15

18

33

33

15  P

15

Iodide- 129 ion

54

76

129

129

53 I-1

53

Chromium-46

24

22

46

46

24   Cr

24

List the number of electrons in each of the following

K1+        O2-               H1+      I      N3-

Gallium-70 ion    Iodide-128 ion

How many neutrons are in:

Chromium-54  Bromine-75

Krypton-82 Iodine-127

ANSWERS

List the number of electrons in each of the following

Potassium Ion 18 electrons

19 Protons - ? = +1   18 e-1

O-2        

Oxide Ion                      10 electrons

16 Protons - ? = -2   18 e-1

H+1                   

Hydrogen Ion                0 electrons

1 Protons - ? = +1   0 e-1

I

Iodine  53 electrons

53 Protons - ? = 0       53 e-1

N-3

Nitride Ion                               10 electrons

19 Protons - ? = +1   18 e-1

Gallium-70 ion  28 electrons  

31 Protons - ? = +3   28 e-1

Iodide-128 ion              54 electrons 

53 Protons - ? = -1   54 e-1

How many neutrons are in:

Chromium-54  (54-24=)30 neutrons

Bromine-75      (75-35=) 40 neutrons

Krypton-82 (82-36=) 46 neutrons

Iodine-127 (127-53=) 74 neutrons

List the number of electrons in each. 

Cr+2            Al+3        Cl-1

Sodium ion

Selenide ion

How many neutrons are in:

Manganese-54 

Sulfur-26

Arsenic-73

ANSWERS

List the number of electrons in each. 

Cr+2            Al+3    Cl-1

Cr+2  22 electrons (24 p-?=+2)

Al+3 10 electrons (13 p-?=+3)

Cl-1  18 electrons (17 p-? =-1)

Sodium ion

Na+1 10 electrons (11 p-?=+1)

Selenide ion

Se-2 36 electrons (34 p-?=-2)

How many neutrons are in:

Manganese-54 

54 AMU -25 P = 29 Neutrons

Sulfur-26

26 AMU -16 P = 10 Neutrons

Arsenic-73

73 AMU -33 P = 40 Neutrons

List the number of electrons.

Cu2            +       F        Fe1+            Mg2+

Polonide ion

Cesium  

List the number of Neutrons for:

Gold-200

Holmium-167

ANSWERS

List the number of electrons.

Cu+2                  27 electrons (29 p-?=+2)

F 9 electrons (9 p-?=0)

Fe+1       25 electrons (26 p-?=+1)    

Mg+2  10 electrons (12 p-?=+2)

Polonide ion

86 electrons (84 p-?=-2)

Cesium

55 electrons (55 p-?=0)

List the number of Neutrons for:

Gold-200  

200AMU -79 P=121 N

Holmium-167 

167AMU -67 P=100 N

List the number of electrons.

Mo1+                 F 1-    Ni               Mn2+

Selenide ion

Astatine 

List the number of Neutrons for:

Tin-120

Bismuth-207

Phosphorus-32

ANSWERS

List the number of electrons.

Mo+1                 41 electrons (42 p-?=+1)

F -1   10 electrons (9 p-?=-1)

Ni  28 electrons (28 p-?=0)      

Mn+223 electrons (25 p-?=+2)

Selenide ion

36 electrons (34 p-?=-2)

Astatine 

85 electrons (85 p-?=0)

List the number of Neutrons for:

Tin-120

120AMU -50 P=70 N

Bismuth-207

207AMU -83 P=124 N

Phosphorus-32

32 AMU-15=17 N

List the number of electrons in each of the following

*****Need to finish****

K             O                   H1-           I1-    N

Gallium-70    Iodide ion-128

31                                                                      54

How many neutrons are in:

Chromium-50  Bromine-78

26                                                          43

Krypton-80 Iodine-125

44                                              72

ANSWERS

List the number of electrons in each of the following

Potassium 19 electrons

19 Protons - ? = 0   19 e-1

O            

Oxygen                         8 electrons

8 Protons - ? = 0   8 e-1

H-1                    

Hydrogen          2 electrons

1 Protons - ? = -1   2 e-1

I-1

Iodine  54 electrons

53 Protons - ? = -1   54 e-1

N

Nitride Ion                               7electrons

7 Protons - ? = 0 7 e-1

Gallium-70 ion  28 electrons  

31 Protons - ? = +3   28 e-1

Iodide-128 ion              54 electrons 

53 Protons - ? = -1   54 e-1

How many neutrons are in:

Chromium-54  (54-24=)30 neutrons

Bromine-75      (75-35=) 40 neutrons

Krypton-82 (82-36=) 46 neutrons

Iodine-127 (127-53=) 74 neutrons