Introduction to Periodic Table worksheet featuring questions on element classification and noble gas configurations.

Problem Analysis:

The worksheet provided is about the Introduction to the Periodic Table. It consists of three main sections:
1. Filling in the correct names of scientists associated with specific contributions to the periodic table.
2. Identifying elements as metals, nonmetals, or metalloids.
3. Writing the noble gas configuration for given elements.

Let's solve each section step by step.

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Section 1: Fill in the correct name.

This section asks you to match the contributions to the periodic table with the names of the scientists who made them. Here are the correct answers:

- (a) Predicted the properties for elements missing from his periodic table:
Dmitri Mendeleev
Mendeleev is famous for predicting the properties of undiscovered elements based on their position in his periodic table.

- (b) Discovered that each element has a unique atomic number:
Henry Moseley
Moseley discovered that the atomic number (number of protons in the nucleus) is the defining characteristic of an element.

- (c) Arranged elements according to the atomic number:
Henry Moseley
After discovering the atomic number, Moseley rearranged the periodic table based on it, which led to a more accurate and systematic organization.

- (d) Arranged elements according to the atomic mass:
John Newlands
Newlands proposed the "Law of Octaves," arranging elements in order of increasing atomic mass, but this method had limitations.

- (e) Had some elements out of place:
John Newlands
Newlands' arrangement based on atomic mass placed some elements incorrectly because he did not account for variations in atomic structure.

- (f) Place all elements in the right place according to properties:
Dmitri Mendeleev
Mendeleev's periodic table was groundbreaking because he arranged elements based on their chemical properties, allowing him to predict the existence and properties of unknown elements.

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Section 2: Identify the following elements as metal, nonmetal, and metalloid.

This section requires knowledge of the classification of elements based on their properties. Here are the classifications:

- (a) Sodium:
Metal
Sodium is a highly reactive alkali metal in Group 1 of the periodic table.

- (b) Chlorine:
Nonmetal
Chlorine is a halogen in Group 17 and is a nonmetal.

- (c) Silicon:
Metalloid
Silicon is located at the boundary between metals and nonmetals and exhibits properties of both. It is a metalloid.

- (d) Iron:
Metal
Iron is a transition metal in Group 8 and is a metal.

- (e) Carbon:
Nonmetal
Carbon is a nonmetal in Group 14 and is essential for life.

- (f) Germanium:
Metalloid
Germanium is another metalloid, located in Group 14, similar to silicon.

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Section 3: Write the noble gas configuration for each of the following elements.

The noble gas configuration is a shorthand way of writing the electron configuration of an element, using the symbol of the nearest noble gas (in the previous period) followed by the additional electrons. Here are the configurations:

- (a) Lithium (Li):
Lithium has an atomic number of 3. Its electron configuration is \(1s^2 2s^1\). The nearest noble gas is Helium (\(He\)), which has an electron configuration of \(1s^2\).
Noble gas configuration: \([He] 2s^1\)

- (b) Magnesium (Mg):
Magnesium has an atomic number of 12. Its electron configuration is \(1s^2 2s^2 2p^6 3s^2\). The nearest noble gas is Neon (\(Ne\)), which has an electron configuration of \(1s^2 2s^2 2p^6\).
Noble gas configuration: \([Ne] 3s^2\)

- (c) Copper (Cu):
Copper has an atomic number of 29. Its electron configuration is \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^1 3d^{10}\). The nearest noble gas is Argon (\(Ar\)), which has an electron configuration of \(1s^2 2s^2 2p^6 3s^2 3p^6\).
Noble gas configuration: \([Ar] 4s^1 3d^{10}\)

- (d) Bromine (Br):
Bromine has an atomic number of 35. Its electron configuration is \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^5\). The nearest noble gas is Krypton (\(Kr\)), which has an electron configuration of \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6\).
Noble gas configuration: \([Ar] 4s^2 3d^{10} 4p^5\)

- (e) Silver (Ag):
Silver has an atomic number of 47. Its electron configuration is \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6 5s^1 4d^{10}\). The nearest noble gas is Krypton (\(Kr\)).
Noble gas configuration: \([Kr] 5s^1 4d^{10}\)

- (f) Tellurium (Te):
Tellurium has an atomic number of 52. Its electron configuration is \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6 5s^2 4d^{10} 5p^4\). The nearest noble gas is Xenon (\(Xe\)), which has an electron configuration of \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^6 5s^2 4d^{10} 5p^6\).
Noble gas configuration: \([Kr] 5s^2 4d^{10} 5p^4\)

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Final Answer:

1. Fill in the correct name:
- (a) Dmitri Mendeleev
- (b) Henry Moseley
- (c) Henry Moseley
- (d) John Newlands
- (e) John Newlands
- (f) Dmitri Mendeleev

2. Identify the elements:
- (a) Sodium: Metal
- (b) Chlorine: Nonmetal
- (c) Silicon: Metalloid
- (d) Iron: Metal
- (e) Carbon: Nonmetal
- (f) Germanium: Metalloid

3. Write the noble gas configuration:
- (a) Lithium: \([He] 2s^1\)
- (b) Magnesium: \([Ne] 3s^2\)
- (c) Copper: \([Ar] 4s^1 3d^{10}\)
- (d) Bromine: \([Ar] 4s^2 3d^{10} 4p^5\)
- (e) Silver: \([Kr] 5s^1 4d^{10}\)
- (f) Tellurium: \([Kr] 5s^2 4d^{10} 5p^4\)

Boxed Final Answer:
\[
\boxed{
\begin{array}{l}
\text{1. (a) Dmitri Mendeleev, (b) Henry Moseley, (c) Henry Moseley, (d) John Newlands, (e) John Newlands, (f) Dmitri Mendeleev} \\
\text{2. (a) Metal, (b) Nonmetal, (c) Metalloid, (d) Metal, (e) Nonmetal, (f) Metalloid} \\
\text{3. (a) [He] 2s^1, (b) [Ne] 3s^2, (c) [Ar] 4s^1 3d^{10}, (d) [Ar] 4s^2 3d^{10} 4p^5, (e) [Kr] 5s^1 4d^{10}, (f) [Kr] 5s^2 4d^{10} 5p^4}
\end{array}
}
\]