When thermal energy is added to a substance, its temperature increases, which can change its state from solid to liquid (melting), liquid to gas (vaporization), or solid to gas (sublimation).

When the pressure exerted on a substance increases, it can cause the substance to condense. Decreasing pressure can cause it to vaporize.

In the solid-state, the individual particles of a substance are in fixed positions with respect to each other because there is not enough thermal energy to overcome the intermolecular interactions between the particles. As a result, solids have a definite shape and volume and molecules are most tightly packed in solids

The Tyndall effect is the phenomenon in which the particles in a colloid scatter the beams of light that are directed at them. This effect is exhibited by all colloidal solutions and some very fine suspensions.
Tyndall effect is exhibited by only milk from the above-mentioned list of solutions.

Lysosomes help to keep the cell clean by digesting any foreign material as well as worn-out cell organelles. Lysosomes are able to do this because they contain powerful digestive enzymes capable of breaking down all organic material.
Mitochondria are strange organelles in the sense that they have their own DNA and ribosomes. Therefore, mitochondria are able to make some of their own proteins.

Stomata are the tiny pores present on the outer layer of the cells, the epidermis. Stomata bring about the exchange of gases and transpiration.
Plastids are present only in plant cells. There are two types of plastids – chloroplasts (coloured plastids) and leucoplasts (white or colourless plastids). Plastids containing the pigment chlorophyll are known as chloroplasts.

The small sized colloidal particles in air can easily scatter a beam of visible light. This scattering of a beam of light is called the Tyndall effect. Under the Tyndall effect, the longer wavelengths are more transmitted while the shorter wavelengths are more diffusely reflected via scattering.

1, 2 and 3

These are explained by Kepler’s laws.

Micronutrients are essential elements that are used by plants in small quantities.

There are 16 elements essential to growth of crop plants:

Supplied by air and water (03): carbon, hydrogen, oxygen

Macronutrients (03): nitrogen, phosphorous, potassium

Secondary Nutrients (03): calcium, magnesium, sulphur

Micronutrients (07): boron (B), chlorine (Cl), copper (Cu), iron (Fe), manganese (Mn), Molybdenum (Mo), and zinc (Zn).

Sound waves are characterised by the motion of particles in the medium and are called mechanical waves. Air is the most common medium through which sound travels. When a vibrating object moves forward, it pushes and compresses the air in front of it creating a region of high pressure.

The gravitational pull exerted by the earth on a body is called its true weight and it is equal to mg (where m is mass of the body and g is the acceleration due to gravity) if the body is not accelerating.

The forces acting on the ball are balanced. Shen resultant force is balanced or zero then object moves in steady state. Since speed is steady, there is no acceleration.

The brain receives information through our five senses: sight, smell, touch, taste, and hearing and thereby controls our thoughts, memory and speech, movement of the arms and legs, and the function of many organs within our body.

The closer the molecules are to each other and the tighter their bonds, the less time it takes for them to pass the sound to each other and the faster sound can travel. It is easier for sound waves to go through solids than through liquid.

Mitochondria are known as the powerhouses of the cell. Mitochondria are strange organelles in the sense that they have their own DNA and ribosomes. Therefore, mitochondria are able to make some of their own proteins.

At the start, the potential energy is mgh and kinetic energy is zero. It is zero because its velocity is zero. The total energy of the object is thus mgh. As it falls, its potential energy will change into kinetic energy.

1, 2 and 3

Generally, the speed of sound decreases when we go from solid to gaseous state. Therefore the speed of sound in steel is greater in steel than in methanol and greater in Methanol than in air.

The speed of sound remains almost the same for all frequencies in a given medium under the same physical conditions.

Citric acid is the principal organic acid found in citrus fruits. To meet increasing demands it is produced from carbohydrate feedstock by fermentation with the fungus Aspergillus niger and the yeasts of Candida.

2 only

1 and 2 only

Both 1 and 2

At the dusk, a wave diverging upwards form a source on or near the surface is refracted continuously away from normal. Now, it is totally reflected and it begins to travel downwards with continuous refraction to reach the observer.

Light waves are many times faster than sound waves. Hence, when there is lightning, the light waves reach us faster than the sound waves.

Earth absorb radiation from sun, and then try to transmit it back to atmosphere, but atmosphere absorb very selective gas as a result of which the gas radiated get back to earth resulting in increase in temperature.

The buoyant force on an object is a result of the gravitational force acting on the surroundings of that object. It is most evident when the object itself is less dense than the surrounding medium.

It is easier to hammer a sharp nail than a blunt one into the wood. This is because blunt nail occupies more area than sharped nail. As pressure exerted it inversely proportional to area lesser the area, the pressure will be more. So the sharp will exert more pressure as it occupies less area.

Every object in the universe attracts every other object with a force which is proportional to the product of their masses and inversely proportional to the square of the distance between them. The force is along the line joining the centres of two objects.

The velocity of sound in air increases as the humidity increases. The density of water vapour is less than dry air.

Every action has an equal and opposite reaction.

It is the tendency of a body to resist change in its state of motion.

Work is said to be done when a force is applied and the body is displaced.