Classification of Elements

What is the main purpose of classifying elements?

• To determine the atomic mass of elements.

• To organize elements based on their properties and behaviors.

• To identify the color of elements.

• To classify elements based on their historical discovery.

Answer explanation

The main purpose of classifying elements is to organize them based on their properties and behaviors, which helps in understanding their relationships and predicting their reactions.

Tags

NGSS.MS-PS1-2

Who created the first real periodic table?

• John Dalton

• Albert Einstein

• Dmitri Mendeleev

• Marie Curie

Answer explanation

Dmitri Mendeleev is credited with creating the first real periodic table in 1869, organizing elements by atomic mass and properties, which laid the foundation for modern chemistry.

In what year did Mendeleev publish his periodic table?

• 1875

• 1886

• 1901

• 1869

Answer explanation

Mendeleev published his periodic table in 1869, organizing elements by atomic mass and properties, which laid the foundation for the modern periodic table. The other years listed do not correspond to this significant event.

How many elements were known at the time of Mendeleev's table?

• 63

• 58

• 50

• 72

Answer explanation

At the time of Mendeleev's periodic table in 1869, 63 elements were known. This number reflects the advancements in chemistry leading up to that period, making 63 the correct choice.

What did Mendeleev use to represent each element in his classification?

• Graphs

• Cards

• Models

• Diagrams

Answer explanation

Mendeleev used cards to represent each element in his classification system. Each card contained information about an element, allowing him to organize and rearrange them effectively to develop the periodic table.

What information was recorded on each card for Mendeleev's elements?

• Atomic weight, chemical properties, and name of each element.

• Density, atomic number, and state of matter for each element.

• Historical discovery date, location, and discoverer of each element.

• Melting point, boiling point, and color of each element.

Answer explanation

Mendeleev's cards included atomic weight, chemical properties, and the name of each element, which were essential for organizing the periodic table and understanding element relationships.

What is one property that Mendeleev noted for each element?

• Atomic mass

• Chemical symbol

• Density

• Melting point

Answer explanation

Mendeleev noted atomic mass as a key property for each element when organizing the periodic table. This helped him predict the properties of undiscovered elements based on their position relative to known elements.

What is the significance of finding relationships between elements?

• It has no impact on understanding or decision-making.

• It complicates the analysis and leads to confusion.

• It only applies to scientific research and not to everyday life.

• It enhances understanding and enables better decision-making.

Answer explanation

Finding relationships between elements enhances understanding by revealing connections and patterns, which leads to better decision-making in various contexts, not just scientific research.

Tags

NGSS.MS-ESS3-4

NGSS.MS-ETS1-1

Who developed the periodic table after Mendeleev?

• John Dalton

• Marie Curie

• Dmitri Mendeleev

• Glenn T. Seaborg

Answer explanation

Glenn T. Seaborg developed the modern periodic table by introducing the actinide series and reorganizing elements based on atomic number, building on Mendeleev's foundational work.

What is the modern periodic table based on?

• The atomic number of elements.

• The chemical properties of elements.

• The mass of elements.

• The color of elements.

Answer explanation

The modern periodic table is organized by the atomic number of elements, which reflects the number of protons in an atom's nucleus. This arrangement highlights the periodicity of chemical properties, making it the most accurate basis for classification.