Atomic Structure Quiz for 10th Class

Period Number in Atomic Structure

• The period number indicates the principal energy level, also referred to as the electron shell, of an atom's outermost electrons.

Noble Gases

• They are found in Group 18 of the periodic table.
• They have a full outer shell of electrons, making them unreactive.

Metallic Character

• Increases down a group and decreases across a period of the periodic table.
• This pattern is due to the decreasing ionization energy down a group and increasing ionization energy across a period.

Atoms in the Same Group

• They have the same number of valence electrons, which are the electrons in the outermost shell.
• This shared characteristic explains their similar chemical properties.

Maximum Electrons in Valence Shell

• The maximum number of electrons that a valence shell can hold is eight, in accordance with the octet rule.

Rutherford's Contribution to Atomic Theory

• He discovered the nucleus of the atom and proposed a model where negatively charged electrons orbit a positively charged center.

Bohr's Addition to the Atomic Model

• He described the quantized energy levels of electrons, meaning electrons can only exist in specific energy levels.
• He introduced the concept of electron orbitals, representing regions of space where electrons are likely to be found.

Electrons in an Atom

• They carry a negative charge.
• They are constantly moving around the nucleus, forming a cloud rather than a specific orbit.

John Dalton's Atomic Theory

• He proposed that atoms were indivisible and indestructible particles.
• He also described atoms as identical for a given element.

The Role of Neutrons

• They are neutral particles found in the nucleus of an atom.
• They contribute to the mass of the atom but not to its charge.

Substances with One Kind of Atom

• These substances are called elements.

Capacity of Electron Shells

• The first shell can hold a maximum of two electrons.
• The second and third shells can hold a maximum of eight electrons.

Democritus' Theory About Atoms

• He proposed that matter is composed of indivisible and indestructible particles which he called atoms.

Negative Ion

• An atom that gains electrons becomes negatively charged, creating a negative ion also known as an anion.

Calcium Ion

• The correct representation is Ca²⁺.

Group of Alkali Metals

• Group 1 contains all the alkali metals.

Atomic Mass

• It represents the average weight of all isotopes of an element.

Key Facts About Noble Gases

• They are colorless and odorless gases at room temperature.
• They are extremely unreactive, due to their full outer shell of electrons.

The Person Who Arranged the Periodic Table

• Dmitri Mendeleev is credited with the arrangement of elements into the periodic table.

John Newlands' Categorization of Elements

• He categorized elements based on their increasing atomic mass.
• He identified patterns of repeating chemical properties every eight elements, known as the Law of Octaves.

Elements Along the Zigzag Line

• They are called metalloids.
• They possess properties of both metals and nonmetals, displaying semiconducting behavior.

Atom Gaining Electrons

• When an atom gains electrons, it becomes a negative ion, also known as an anion, due to the increased negative charge.

Atoms with the Same Atomic Number

• They are classified as the same element, because the atomic number defines the number of protons in the nucleus, which is the defining characteristic of an element.