Explanation

• Distillation involves boiling water to produce steam, which is then condensed back into liquid water, leaving behind most contaminants (salts, heavy metals, and many microorganisms).
• It's one of the most effective methods for purifying contaminated water.

Additional information

• Agriculture — refers to farming, not purification.
• Adding salts — would make water more contaminated, not less.
• Adding detergents — detergents are pollutants themselves and would contaminate the water further

Explanation

• Air pressure decreases as altitude increases.
• At higher altitudes, there is less air above us.
• Therefore, the weight of the air column is lower.
• Air becomes less dense at higher altitudes.
• So, higher altitude = lower air pressure.

Explanation

• Life can't sustain itself without water
• It is needed for important biological processes.
• Plants require water for photosynthesis.
• Animals need water for survival and body functions.

Explanation

• Conduction: Heat transfer through direct contact between particles.
• Convection: Heat transfer through the movement of liquids or gases.
• Radiation: Heat transfer through electromagnetic waves.
• The Sun heats the Earth by radiation.
• Heat naturally moves from a hotter body to a colder body.

Explanation

The law is Newton's Law of Universal Gravitation.

• It states that gravitational force is directly proportional to the product of two masses.
• It is inversely proportional to the square of the distance between them.
• Formula: F = Gx m_1m_2/r^2
• G is the universal gravitational constant.
• The force acts between any two masses.

Explanation

• The nucleus of an atom contains protons and neutrons.
• The nucleus is the central part of an atom.
• Protons have a positive charge.
• Neutrons have no electric charge.
• Electrons are found outside the nucleus
• The nucleus makes up much less than. 01% of the volume of the atom,
• But typically contains more than 99.9% of the mass of the atom.

Explanation

Materials are classified based on how they conduct heat.

- Conductors: Allow heat to pass through easily (e.g., metals like copper, iron).

- Insulators: Do not allow heat to flow through easily.

- Examples of insulators: Wood, plastic, rubber, glass.

- Used in cooking handles, thermal flasks, and electrical wire coatings.

Explanation

Important: Simply adding more product does not permanently increase Kc; it changes the reaction quotient until equilibrium is restored.

• Kc is the equilibrium constant.
• A larger Kc generally indicates equilibrium favors products.
• At equilibrium, the value of Kc depends on temperature.
• A catalyst does not change Kc.

Explanation

• Kc is the equilibrium constant based on concentration.
• A small Kc means equilibrium favors the reactants.
• Therefore, more reactants remain at equilibrium.
• Only a small amount of products is formed.
• A large Kc  indicates that equilibrium favors the products.

Explanation

• Kinematics is the study of motion.
• It describes position, velocity, and acceleration.
• It does not focus on the forces causing motion.
• Examples include linear motion, circular motion, and projectile motion.

Additional information

• Mechanics → broad branch of physics dealing with motion and forces.
• Dynamics → studies motion and the forces causing it.