Question

1. *complete the table below based on the models provided.

number of protons atom i atom ii
number of neutrons
mass number
atom i atom ii

1. **write an atomic symbol for each of the atoms in question 1.

a. atom i:
b. atom ii:

1. **write the isotopic name of the atom for each of the atoms in question 1.

a. atom i:
b. atom ii:

1. **based on the information provided, identify the pair that contains isotopes of the same element.

(a) ^195_78pt and ^197_78pt
(b) ^3_2he and ^3_1h
(c) ^59_23v and ^59_23v
(d) ^72_33as and ^75_33as

1. **which element contains the largest number of neutrons per atom?

(a) bismuth - 210
(b) polonium - 210
(c) astatine - 210
(d) astatine - 211

1. *an atom of a substance that contains 14 protons and 30 neutrons is likely an isotope of

(a) sulfur
(b) strontium
(c) silicon
(d) zirconium

1. an atom of a substance that contains 10 protons and 23 neutrons is likely an isotope of

(a) vanadium
(b) neon
(c) aluminum
(d) calcium

1. which sample has the greatest nuclear charge (protons)?

(a) calcium
(b) lithium
(c) strontium
(d) chlorine

1. *can two atoms with the same mass number ever be isotopes of each other? explain.
2. in terms of protons and neutrons, how are ^27_13al and ^29_13al similar and different?

consult the following list of isotope symbols: ^204_82pb, ^82_35br, ^78_35br, ^208_82pb, ^204_78pt, ^205_82pb.

1. **which of the atoms represented by these symbols are isotopes of each other?

Explanation:

Step1: Recall isotope definition

Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.

Step2: Analyze question 4

For option (A) $^{195}_{78}Pt$ and $^{197}_{78}Pt$, they have the same atomic number (78, which means same number of protons), so they are isotopes. For option (B) $^{3}_{2}He$ and $^{3}_{1}H$ have different atomic numbers. For option (C) $^{50}_{23}V$ and $^{51}_{23}V$ are isotopes. For option (D) $^{72}_{33}As$ and $^{75}_{33}As$ are isotopes.

Step3: Analyze question 5

Calculate number of neutrons for each option. For Bismuth - 210 ($Bi$ has atomic number 83), number of neutrons = 210 - 83=127. For Polonium - 210 ($Po$ has atomic number 84), number of neutrons = 210 - 84 = 126. For Astatine - 210 ($At$ has atomic number 85), number of neutrons = 210 - 85 = 125. For Astatine - 211, number of neutrons = 211 - 85 = 126. So Bismuth - 210 has the most neutrons.

Step4: Analyze question 6

An atom with 14 protons is Silicon ($Si$) according to the periodic - table.

Step5: Analyze question 7

An atom with 10 protons is Neon ($Ne$) according to the periodic - table.

Step6: Analyze question 8

Nuclear charge is determined by number of protons. Calcium ($Ca$) has 20 protons, Lithium ($Li$) has 3 protons, Strontium ($Sr$) has 38 protons, Chlorine ($Cl$) has 17 protons. So Strontium has the greatest nuclear charge.

Step7: Analyze question 9

No, two atoms with the same mass number cannot be isotopes of each other. Isotopes have the same number of protons but different mass numbers due to different number of neutrons. If mass numbers are the same and number of protons is the same, then number of neutrons is the same too, so they are the same atom, not isotopes.

Step8: Analyze question 10

$^{27}_{13}Al$ and $^{29}_{13}Al$ both have 13 protons (same element). $^{27}_{13}Al$ has 27 - 13=14 neutrons and $^{29}_{13}Al$ has 29 - 13 = 16 neutrons. So they have the same number of protons but different number of neutrons.

Step9: Analyze question 11

Isotopes have the same atomic number. $^{204}_{82}Pb$, $^{206}_{82}Pb$ and $^{207}_{82}Pb$ are isotopes of each other as they all have atomic number 82. $^{82}_{35}Br$ and $^{78}_{35}Br$ are isotopes of each other as they have atomic number 35.

Answer:

1. A, C, D
2. A
3. C
4. B
5. C
6. No, two atoms with the same mass number cannot be isotopes of each other. Isotopes have the same number of protons but different mass numbers due to different number of neutrons. If mass numbers are the same and number of protons is the same, then number of neutrons is the same too, so they are the same atom, not isotopes.
7. They have the same number of protons (13), but $^{27}_{13}Al$ has 14 neutrons and $^{29}_{13}Al$ has 16 neutrons.
8. $^{204}_{82}Pb$, $^{206}_{82}Pb$ and $^{207}_{82}Pb$ are isotopes of each other; $^{82}_{35}Br$ and $^{78}_{35}Br$ are isotopes of each other.