Chemistry Notes Ssc !free! -

Tendency to attract shared electrons. Fluorine is the most electronegative element. 4. Acids, Bases, and Salts

: Increases (Fluorine is the most electronegative element). Metallic Character : Decreases. 4. Chemical Bonding and Reactions

Pure substances formed by chemically combining two or more elements in a fixed ratio (e.g., Water - H2Ocap H sub 2 cap O NaClcap N a cap C l

18 groups. Elements in the same group have similar properties. Periods (Horizontal Rows): 7 periods. Key Trends: chemistry notes ssc

Atoms having the same number of neutrons (e.g., Carbon-14 and Oxygen-16, both have 8 neutrons). 3. The Periodic Table

This is one of the highest-yielding topics for SSC examinations. Direct questions regarding properties and pH levels are common. Sour taste. Turn blue litmus paper red. Release Hydrogen ions ( H+cap H raised to the positive power ) in aqueous solutions. Strong Acids: HClcap H cap C l H2SO4cap H sub 2 cap S cap O sub 4 HNO3cap H cap N cap O sub 3 Weak Acids: CH3COOHcap C cap H sub 3 cap C cap O cap O cap H (Acetic acid), Citric acid. Bitter taste. Soapy touch. Turn red litmus paper blue. Release Hydroxyl ions ( OH−cap O cap H raised to the negative power

: Be familiar with atmospheric layers, the greenhouse effect, and causes of air pollution. 2. Essential "One-Liners" for Quick Revision Tendency to attract shared electrons

The modern periodic table organizes elements based on their increasing atomic number, a system formulated by Henry Moseley. Structure of the Periodic Table 7 horizontal rows. Groups: 18 vertical columns. Group 1: Alkali Metals (highly reactive, soft). Group 2: Alkaline Earth Metals.

States that the physical and chemical properties of elements are periodic functions of their (unlike Mendeleev's table, which relied on atomic masses).

Low pH = High H⁺ (acidic)

: Unsaturated hydrocarbons with at least one triple bond. General formula: CnH2n−2cap C sub n cap H sub 2 n minus 2 end-sub 8. Common Chemical Names, Formulas, and Everyday Uses

This is one of the most frequently tested topics in SSC CGL and CHSL. Indicator/Property pH < 7; turns Blue Litmus Red Sour; H+ donors (e.g., Vinegar = Acetic Acid) Base pH > 7; turns Red Litmus Blue Bitter; OH– donors Neutral Examples: Pure water, NaCl Common Acids in Nature: Vinegar : Acetic acid Citrus Fruits : Citric acid Sour Milk/Curd : Lactic acid Ant Stings : Formic acid 3. Chemistry in Everyday Life (High Weightage)

Indefinite shape, indefinite volume, highly compressible, low density. Acids, Bases, and Salts : Increases (Fluorine is