Explanation

• A mixture contains two or more substances physically combined, which can be separated by physical means.
• Examples include sharbat, tea, steel.
• Common salt (NaCl) is a pure compound, not a mixture.

Last verified on 18-03-2026

Explanation

• Phosphorus (P), Potassium (K), and Nitrogen (N) are three essential macronutrients for plant growth.
• It is also referred to as "NPK".
• They play critical roles in various plant processes, including photosynthesis, root development, and cell growth.

Last verified on 17-03-2026

Explanation

• Ions are charged particles formed when an atom gains or loses electrons.
• Loss of electrons creates a positively charged ion (cation).
• Gain of electrons creates a negatively charged ion (anion).

Last verified on 17-03-2026

Explanation

• A change in physical appearance or state of a substance, such as a change in shape, size, color, or phase (solid, liquid, gas), is called a Physical Change.
  

The are examples of Physical Changes:

• Melting (ice cream, wax, chocolate, ice and change from solid to liquid)
• Phase changes (boiling, freezing, condensation)
• Crushing (chalk)
• Tearing (paper)
• Crumpling (aluminium foil)
• Stretching (rubber band)
• Mixing (sugar in water)
• Dissolving (sugar, salt in water)
• Moulding (clay, metals)
• Slicing (fruit)
• Forming of frost (from water vapors)
• Transition to a gas (change from liquid to gas)
• Change of durability (change in texture or strength)
• Changes to crystal form (change in crystal structure)

Last verified on 17-03-2026

Explanation

• Dilution refers to the process of decreasing the concentration of a solution by adding more solvent.
• While ionisation involves the formation of ions from molecules in a solution.

Last verified on 16-03-2026

Explanation

• Citric acid is a natural preservative found in many fruits, particularly in citrus fruits like lemons, oranges, and grapefruits.
• It's responsible for their sour taste and is also used as a food additive.
• Other fruits like mangoes, grapes, and strawberries also contain citric acid, although in smaller amounts.
• The presence of citric acid gives these fruits their characteristic sour taste.

Last verified on 16-03-2026

Explanation

• Bases are substances that have a soapy or slippery feel when touched.
• This property occurs because bases react with oils on the skin, giving a soap-like texture.
• Many bases also turn red litmus paper blue in chemical tests.
• Common bases are used in cleaning agents, soaps, and detergents.

Last verified on 16-03-2026

Explanation

• Sonorousness is the property of metals that allows them to produce a ringing sound when struck.
• Because of this property, metals are used to make bells, gongs, and musical instruments.
• Metals like bronze and brass produce clear sounds when vibrated.
• This is why metallic materials are preferred in musical sound-producing objects.

Last verified on 16-03-2026

Explanation

• Copper is a chemical element with the symbol Cu and atomic number 29. 
• It is a soft, malleable, and ductile metal with a reddish-orange color.

The some major elements with their symbols:

• Hydrogen - H
• Sodium - Na
• Carbon - C
• Nitrogen - N
• Oxygen - O
• Fluorine - F
• Chlorine - Cl
• Potassium - K
• Helium - He
• Neon - Ne
• Calcium - Ca
• Sulphur - S
• Phosphorus - P
• Aluminium - Al
• Magnesium - Mg
• Iron - Fe

Last verified on 16-03-2026

Explanation

• A solid has both a definite shape and a definite volume.
• The particles in solids are tightly packed and only vibrate in fixed positions.
• Examples include iron, wood, stone, and ice.

Additional information:

• A liquid has a definite volume but no definite shape.
• A gas has neither definite shape nor definite volume.