Periodic Table

Question 1

Arrangement of periodic table

-Definition
- Where are Metals & Non Metals

-Group Number
-What do elements in same group share?

-Period Number
-What do elements in same period share?

Answer 1

Periodic Table: Arrangement of elements in periods (rows) and groups (columns) by increasing proton number/atomic number.

Metallic character decreases across a period from left to right, while non-metallic character increases.

Group number corresponds to the number of valence electrons.
Elements in a group tend to form ions with charges equal to their group number.

Elements in the same group have identical electronic configurations.

Period number corresponds to the number of orbital shells in the electronic configuration of element.

Atomic size generally decreases across a period.
Electronegativity tends to increase across a period.

Question 2

Group I Elements / Alkali Metals

• Trends
• Characteristics

Answer 2

Trends down the group:
- Decreasing melting point
- Increasing density
- Increasing reactivity

Characteristics:
- Relatively soft metals.

Question 3

Group VII Elements / Halogens

• Common Characteristics
• Appearance of Cl, Br & I
• Halide Definitions
• Displacement Reactions

Answer 3

Common characteristics:
1. Diatomic non-metals.
2. Increasing density: Density increases down the group
3. Decreasing reactivity: Reactivity decreases down the group, especially in reactions with metals.

Physical states:
1. Chlorine: Pale yellow-green
2. Bromine: Red-brown liquid
3. Iodine: Grey-black solid

Halides: Compounds formed when halogens react with metals, e.g., sodium chloride (NaCl).

Displacement reactions: More reactive halogens displace less reactive halogens in solutions containing their ions, with higher halogens displacing lower ones.

Question 4

Group VII Elements / Noble Gases

• Characteristics
• Why do they behave like this?

Answer 4

Group VIII noble gases are
-Unreactive: They rarely undergo chemical reactions due to their stable, inert nature.

• Monatomic: They exist as single atoms rather than diatomic molecules or ions.

This behavior can be explained by their electronic configuration:
- Noble gases have a complete outer electron shell.

• Their outer electron shells are fully occupied, making them stable and chemically inert.
• Due to the filled outer electron shells, noble gases have little tendency to gain, lose, or share electrons with other elements, leading to their unreactive nature.

Question 5

Transition Metals
- Characteristics
- Properties
- Used as?
- Attributes

Answer 5

• Transition elements: dense metals with high melting points
• Known for: forming colorful compounds
• Act as catalysts in various chemical reactions
• Attributes: unique electronic configurations, including partially filled orbitals, enabling diverse chemical behaviors