Atomic Number, Mass Number, Isotopes, And Stuff Worksheet - Free Printable

Problem Analysis:

The worksheet focuses on understanding atomic number, mass number, isotopes, and related concepts. Here's a breakdown of the tasks:

1. Complete the following questions: For each isotope given in the table, identify the element, the number of protons, neutrons, and electrons.
2. Write the symbol for the isotope: Based on the given information (protons and neutrons or atomic number and mass number), write the isotope symbol.

Solution:

#### Part 1: Complete the following questions

Each isotope is represented in the format $^A_ZX$, where:
- \( A \) is the mass number (total number of protons and neutrons).
- \( Z \) is the atomic number (number of protons).
- The element symbol \( X \) identifies the element.

For neutral atoms, the number of electrons equals the number of protons (\( Z \)).

##### Isotope 1: $^4_2\text{He}$
- Element: Helium (He)
- # protons: 2 (from the subscript \( Z = 2 \))
- # neutrons: \( A - Z = 4 - 2 = 2 \)
- # electrons: 2 (equal to the number of protons)

##### Isotope 2: $^{56}_{26}\text{Fe}$
- Element: Iron (Fe)
- Atomic #: 26 (from the subscript \( Z = 26 \))
- Mass #: 56 (from the superscript \( A = 56 \))
- # electrons: 26 (equal to the number of protons)

##### Isotope 3: $^{27}_{13}\text{Al}$
- Element: Aluminum (Al)
- # protons: 13 (from the subscript \( Z = 13 \))
- # neutrons: \( A - Z = 27 - 13 = 14 \)
- # electrons: 13 (equal to the number of protons)

##### Isotope 4: $^{40}_{20}\text{Ca}$
- Element: Calcium (Ca)
- # protons: 20 (from the subscript \( Z = 20 \))
- # neutrons: \( A - Z = 40 - 20 = 20 \)
- # electrons: 20 (equal to the number of protons)

##### Isotope 5: $^{20}_{10}\text{Ne}$
- Element: Neon (Ne)
- Atomic #: 10 (from the subscript \( Z = 10 \))
- # electrons: 10 (equal to the number of protons)
- Atomic mass: 20 (from the superscript \( A = 20 \))

##### Isotope 6: $^{14}_{6}\text{C}$
- Element: Carbon (C)
- # protons: 6 (from the subscript \( Z = 6 \))
- # electrons: 6 (equal to the number of protons)
- # neutrons: \( A - Z = 14 - 6 = 8 \)

##### Isotope 7: $^{19}_{9}\text{F}$
- Element: Fluorine (F)
- Atomic #: 9 (from the subscript \( Z = 9 \))
- Mass #: 19 (from the superscript \( A = 19 \))
- # electrons: 9 (equal to the number of protons)

##### Isotope 8: $^{1}_{1}\text{H}$
- Element: Hydrogen (H)
- Atomic #: 1 (from the subscript \( Z = 1 \))
- # electrons: 1 (equal to the number of protons)
- # neutrons: \( A - Z = 1 - 1 = 0 \)

##### Isotope 9: $^{2}_{1}\text{H}$
- Element: Hydrogen (H)
- # protons: 1 (from the subscript \( Z = 1 \))
- # electrons: 1 (equal to the number of protons)
- # neutrons: \( A - Z = 2 - 1 = 1 \)

#### Part 2: Write the symbol for the isotope

To write the isotope symbol, use the format $^A_ZX$, where:
- \( A \) is the mass number (\( Z + N \)).
- \( Z \) is the atomic number (number of protons).
- \( X \) is the element symbol.

##### a. With 8 protons and 8 neutrons
- Atomic number (\( Z \)): 8
- Mass number (\( A \)): \( Z + N = 8 + 8 = 16 \)
- Element: Oxygen (O) [atomic number 8]
- Symbol: $^{16}_8\text{O}$

##### b. With 28 protons and 30 neutrons
- Atomic number (\( Z \)): 28
- Mass number (\( A \)): \( Z + N = 28 + 30 = 58 \)
- Element: Nickel (Ni) [atomic number 28]
- Symbol: $^{58}_{28}\text{Ni}$

##### c. With atomic # 11 and mass # of 23
- Atomic number (\( Z \)): 11
- Mass number (\( A \)): 23
- Element: Sodium (Na) [atomic number 11]
- Symbol: $^{23}_{11}\text{Na}$

##### d. With 92 protons and mass # 238
- Atomic number (\( Z \)): 92
- Mass number (\( A \)): 238
- Element: Uranium (U) [atomic number 92]
- Symbol: $^{238}_{92}\text{U}$

#### Final Answer:

1. Completed Table:
- $^4_2\text{He}$: Helium, 2 protons, 2 neutrons, 2 electrons
- $^{56}_{26}\text{Fe}$: Iron, 26 protons, 30 neutrons, 26 electrons
- $^{27}_{13}\text{Al}$: Aluminum, 13 protons, 14 neutrons, 13 electrons
- $^{40}_{20}\text{Ca}$: Calcium, 20 protons, 20 neutrons, 20 electrons
- $^{20}_{10}\text{Ne}$: Neon, 10 protons, 10 neutrons, 10 electrons
- $^{14}_{6}\text{C}$: Carbon, 6 protons, 8 neutrons, 6 electrons
- $^{19}_{9}\text{F}$: Fluorine, 9 protons, 10 neutrons, 9 electrons
- $^{1}_{1}\text{H}$: Hydrogen, 1 proton, 0 neutrons, 1 electron
- $^{2}_{1}\text{H}$: Hydrogen, 1 proton, 1 neutron, 1 electron

2. Isotope Symbols:
- a. $^{16}_8\text{O}$
- b. $^{58}_{28}\text{Ni}$
- c. $^{23}_{11}\text{Na}$
- d. $^{238}_{92}\text{U}$

Boxed Final Answer:

\[
\boxed{
\begin{array}{l}
\text{1. Completed Table:} \\
\text{- } ^4_2\text{He: Helium, 2 protons, 2 neutrons, 2 electrons} \\
\text{- } ^{56}_{26}\text{Fe: Iron, 26 protons, 30 neutrons, 26 electrons} \\
\text{- } ^{27}_{13}\text{Al: Aluminum, 13 protons, 14 neutrons, 13 electrons} \\
\text{- } ^{40}_{20}\text{Ca: Calcium, 20 protons, 20 neutrons, 20 electrons} \\
\text{- } ^{20}_{10}\text{Ne: Neon, 10 protons, 10 neutrons, 10 electrons} \\
\text{- } ^{14}_{6}\text{C: Carbon, 6 protons, 8 neutrons, 6 electrons} \\
\text{- } ^{19}_{9}\text{F: Fluorine, 9 protons, 10 neutrons, 9 electrons} \\
\text{- } ^{1}_{1}\text{H: Hydrogen, 1 proton, 0 neutrons, 1 electron} \\
\text{- } ^{2}_{1}\text{H: Hydrogen, 1 proton, 1 neutron, 1 electron} \\
\\
\text{2. Isotope Symbols:} \\
\text{- a. } ^{16}_8\text{O} \\
\text{- b. } ^{58}_{28}\text{Ni} \\
\text{- c. } ^{23}_{11}\text{Na} \\
\text{- d. } ^{238}_{92}\text{U} \\
\end{array}
}
\]