Class 5 Science HOTS Questions - Solids, Liquids and Gases

Q1: Which of the following states of matter is the most compressible?
(a) Solid
(b) Liquid
(c) Gas
(d) Plasma
Ans: (c)
Gases are highly compressible compared to solids and liquids. When pressure is applied to a gas, its particles can be squeezed closer together, leading to a decrease in volume. This property allows gases to fill containers completely and evenly, even if the container's shape changes.

Q2: Riya performed an experiment where she heated a solid, and it directly turned into a gaseous state without passing through the liquid state. Which process is responsible for this transformation?
(a) Condensation
(b) Sublimation
(c) Evaporation
(d) Fusion
Ans: (b)
Sublimation is the process in which a solid directly changes into a gas without going through the liquid state. During sublimation, the particles of the solid gain enough energy to break free from their fixed positions and enter the gaseous state. This phenomenon is observed in certain substances like dry ice (solid carbon dioxide) and mothballs (naphthalene).

Q3: When water evaporates from the surface of leaves of a plant, what is the main purpose of this process?
(a) To help the plant grow taller
(b) To cool down the plant
(c) To attract insects for pollination
(d) To store excess water
Ans: (b)
The process of evaporation from the leaves is known as transpiration. One of the main purposes of transpiration is to cool down the plant. As water evaporates from the surface of the leaves, it releases heat energy, which helps in regulating the plant's temperature. Additionally, transpiration also helps in the movement of water and nutrients from the roots to other parts of the plant.

Q4: A steel container was filled with water and tightly sealed. The container was then heated over a flame. What will most likely happen to the container?
(a) The container will remain unchanged
(b) The container will expand and eventually burst
(c) The container will shrink and collapse
(d) The container will develop a hole and leak
Ans: (b)
When water is heated, it undergoes thermal expansion, causing its volume to increase. As the water inside the steel container heats up, it will also expand. Since the container is tightly sealed, the increasing pressure inside the container due to the expanding water may eventually lead to the container bursting if the pressure exceeds the container's strength.

Q5: Which of the following statements about gases is true?
(a) Gases have definite shape and volume.
(b) Gases have particles that are tightly packed together.
(c) Gases can be easily compressed into smaller volumes.
(d) Gases have high density compared to liquids.
Ans: (c)
Gases have particles that are widely spaced and move freely. Since the particles in a gas have significant gaps between them, gases can be easily compressed by reducing the space between the particles. This property of gases makes them highly compressible, unlike solids and liquids, which have more closely packed particles.

Q6: During the process of freezing, the arrangement of particles in a substance:
(a) Becomes more disordered
(b) Remains the same
(c) Becomes more closely packed
(d) Changes from a liquid state to a gas state
Ans: (c)
During freezing, a substance changes from the liquid state to the solid state. As the substance loses heat energy, its particles lose kinetic energy and slow down. This causes the particles to arrange themselves in a more ordered and closely packed structure, resulting in the formation of a solid with a definite shape.

Q7: The property of liquids that allows them to form a curved meniscus in a narrow tube is primarily due to:
(a) Viscosity
(b) Surface tension
(c) Evaporation
(d) Expansion
Ans: (b)
Surface tension is the property of a liquid that causes its surface to behave like an elastic sheet. It is responsible for the formation of a curved meniscus in a narrow tube because the liquid molecules at the surface experience a net inward force, which pulls the liquid inward and forms the curved shape.

Q8: Which of the following statements about the three states of matter is correct?
(a) Solids have fixed shape and volume, while gases have a variable shape and volume.
(b) Solids have variable shape and volume, while liquids have a fixed shape and volume.
(c) Solids, liquids, and gases have fixed shapes and volumes.
(d) Solids, liquids, and gases have variable shapes and volumes.
Ans: (a)
Solids have a fixed shape and volume because their particles are tightly packed and have minimal movement. On the other hand, gases have a variable shape and volume since their particles are widely spaced and have high kinetic energy, allowing them to fill the entire container they are in, taking its shape.

Q9: Which of the following statements about the intermolecular forces in solids, liquids, and gases is true?
(a) Intermolecular forces are strongest in gases and weakest in solids.
(b) Intermolecular forces are strongest in liquids and weakest in gases.
(c) Intermolecular forces are equally strong in all three states of matter.
(d) Intermolecular forces are strongest in solids and weakest in liquids.
Ans: (d)
Intermolecular forces are the attractive forces between particles in a substance. In solids, the particles are closely packed and held together by strong intermolecular forces, resulting in a definite shape. In liquids, the particles are more loosely packed than in solids, and the intermolecular forces are weaker, allowing them to flow and take the shape of their container. In gases, the particles are far apart, and the intermolecular forces are the weakest, allowing gases to expand to fill the entire container.

Q10: Which of the following phenomena is an example of a physical change?
(a) Burning of wood
(b) Rusting of iron
(c) Melting of ice
(d) Digestion of food
Ans: (c)
Melting of ice is a physical change because it involves a change in the state of water from a solid (ice) to a liquid (water) without altering the chemical composition of the substance. Physical changes are reversible, and in the case of melting, ice can be frozen back into a solid state without any change in its chemical properties. Burning of wood, rusting of iron, and digestion of food are examples of chemical changes as they involve the formation of new substances with different chemical properties.