Frequently Asked Questions About the Periodic Table

Oct 13, 2025 by wbrum.org 131 views

Determining the Number of Atoms of Phosphorus in a Sample

The periodic table is a fundamental tool in chemistry that provides a wealth of information about the elements, including their atomic masses and symbols. In this article, we will explore how to use the periodic table to determine the number of atoms of phosphorus (P) in a sample with a mass of 172.90 g.

Understanding the Atomic Mass of Phosphorus

To begin, we need to understand the atomic mass of phosphorus. The atomic mass of an element is the average mass of a single atom of that element, expressed in units of atomic mass units (amu). The atomic mass of phosphorus is 30.97 amu.

Converting Mass to Number of Atoms

To determine the number of atoms of phosphorus in a sample, we need to convert the mass of the sample from grams to atoms. We can do this using the following formula:

Number of atoms = (mass of sample in grams) x (Avogadro's number) / (atomic mass of phosphorus in amu)

Where Avogadro's number is a constant that represents the number of atoms in one mole of a substance, which is equal to 6.022 x 10^23 atoms/mol.

Calculating the Number of Atoms

Now, let's plug in the values we know into the formula:

Number of atoms = (172.90 g) x (6.022 x 10^23 atoms/mol) / (30.97 amu)

First, we need to convert the mass of the sample from grams to moles:

Mass in moles = mass in grams / atomic mass = 172.90 g / 30.97 amu = 5.58 mol

Now, we can plug this value into the formula:

Number of atoms = (5.58 mol) x (6.022 x 10^23 atoms/mol) / (30.97 amu) = 1.04 x 10^24 atoms

Comparing the Result to the Options

Now that we have calculated the number of atoms of phosphorus in the sample, we can compare our result to the options provided:

A. $3.48 \times 10^{21}$ atoms B. $1.97 \times 10^{22}$ atoms C. $3.36 \times 10^{24}$ atoms D. $1.04 \times 10^{24}$ atoms

Our result, $1.04 \times 10^{24}$ atoms, matches option D.

Conclusion

In this article, we used the periodic table to determine the number of atoms of phosphorus in a sample with a mass of 172.90 g. We first converted the mass of the sample from grams to moles, and then used the formula to calculate the number of atoms. Our result matched option D, which is $1.04 \times 10^{24}$ atoms.

Understanding the Importance of the Periodic Table

The periodic table is a powerful tool in chemistry that provides a wealth of information about the elements. By using the periodic table, we can determine the number of atoms of an element in a sample, as well as other important properties such as the atomic mass and symbol.

Real-World Applications of the Periodic Table

The periodic table has many real-world applications, including:

Chemical analysis: The periodic table is used to identify the elements present in a sample, as well as their concentrations.
Materials science: The periodic table is used to design and develop new materials with specific properties.
Pharmaceuticals: The periodic table is used to develop new medicines and treatments.
Energy production: The periodic table is used to develop new energy sources and improve the efficiency of existing ones.

Conclusion

In conclusion, the periodic table is a powerful tool in chemistry that provides a wealth of information about the elements. By using the periodic table, we can determine the number of atoms of an element in a sample, as well as other important properties such as the atomic mass and symbol. The periodic table has many real-world applications, including chemical analysis, materials science, pharmaceuticals, and energy production.
Frequently Asked Questions About the Periodic Table

The periodic table is a fundamental tool in chemistry that provides a wealth of information about the elements. In this article, we will answer some of the most frequently asked questions about the periodic table.

Q: What is the periodic table?

A: The periodic table is a tabular arrangement of the elements, organized by their atomic number (number of protons in the nucleus), electron configuration, and recurring chemical properties. The elements are listed in order of increasing atomic number (number of protons in the nucleus) and are grouped into rows called periods and columns called groups.

Q: What is the purpose of the periodic table?

A: The periodic table serves several purposes:

Organization: The periodic table organizes the elements in a logical and systematic way, making it easier to find and compare the properties of different elements.
Prediction: The periodic table allows us to predict the properties of elements that have not yet been discovered or synthesized.
Classification: The periodic table classifies the elements into different groups and periods, based on their chemical properties and electron configurations.

Q: How is the periodic table organized?

A: The periodic table is organized in a specific way:

Rows (periods): The elements are listed in order of increasing atomic number (number of protons in the nucleus) in rows called periods.
Columns (groups): The elements are grouped into columns called groups, based on their chemical properties and electron configurations.
Blocks: The elements are also grouped into blocks, based on their electron configuration.

Q: What are the different blocks of the periodic table?

A: The periodic table is divided into four blocks:

s-block: The s-block elements are located in the first two columns of the periodic table and include the alkali metals and alkaline earth metals.
p-block: The p-block elements are located in the right-hand side of the periodic table and include the nonmetals and metalloids.
d-block: The d-block elements are located in the middle of the periodic table and include the transition metals.
f-block: The f-block elements are located at the bottom of the periodic table and include the lanthanides and actinides.

Q: What are the different groups of the periodic table?

A: The periodic table is divided into 18 groups:

Group 1 (alkali metals): The elements in group 1 are highly reactive and include lithium, sodium, and potassium.
Group 2 (alkaline earth metals): The elements in group 2 are less reactive than the alkali metals and include magnesium and calcium.
Group 13 (boron group): The elements in group 13 are metalloids and include boron, aluminum, and gallium.
Group 14 (carbon group): The elements in group 14 are nonmetals and include carbon, silicon, and germanium.
Group 15 (nitrogen group): The elements in group 15 are nonmetals and include nitrogen, phosphorus, and arsenic.
Group 16 (chalcogens): The elements in group 16 are nonmetals and include oxygen, sulfur, and selenium.
Group 17 (halogens): The elements in group 17 are highly reactive and include fluorine, chlorine, and iodine.
Group 18 (noble gases): The elements in group 18 are unreactive and include helium, neon, and argon.

Q: What is the difference between a metal and a nonmetal?

A: Metals and nonmetals are two types of elements that have different properties:

Metals: Metals are typically shiny, malleable, and good conductors of electricity. They include elements such as iron, copper, and gold.
Nonmetals: Nonmetals are typically dull, brittle, and poor conductors of electricity. They include elements such as carbon, nitrogen, and oxygen.

Q: What is the difference between a metalloid and a nonmetal?

A: Metalloids are elements that have properties of both metals and nonmetals:

Metalloids: Metalloids are typically semiconductors and have properties of both metals and nonmetals. They include elements such as silicon, germanium, and arsenic.

Q: What is the difference between a transition metal and a nontransition metal?

A: Transition metals and nontransition metals are two types of elements that have different properties:

Transition metals: Transition metals are typically good conductors of electricity and have a high melting point. They include elements such as iron, copper, and gold.
Nontransition metals: Nontransition metals are typically poor conductors of electricity and have a low melting point. They include elements such as carbon, nitrogen, and oxygen.

Q: What is the difference between a lanthanide and an actinide?

A: Lanthanides and actinides are two types of elements that have different properties:

Lanthanides: Lanthanides are a series of elements that are located in the bottom left corner of the periodic table. They include elements such as lanthanum, cerium, and neodymium.
Actinides: Actinides are a series of elements that are located in the bottom right corner of the periodic table. They include elements such as actinium, thorium, and uranium.

Conclusion

In conclusion, the periodic table is a fundamental tool in chemistry that provides a wealth of information about the elements. By understanding the organization and properties of the elements, we can predict and classify the elements in a logical and systematic way.