How Does Water Change Its State?
Can you imagine your life without water? If your answer is no, then can you at least imagine a day without water? Still, your answer is no!! yeah because as soon as you wake up you start using water. Water is one of our basic needs. It is a necessity for human survival and civilization. Human existence is possible on earth as it has a large amount of water. If you observe a globe, you will find a large area that is blue in colour which indicates the presence of water there. About 71% of the earth’s surface is covered by water. Even 70% of our body is made up of water. These facts clearly describe the importance of water for the existence of ecosystems. Basically, water exists in three forms on earth and its atmosphere. Those three forms of water are as follows –
Water in Solid Form (Ice)
Water in Liquid Form (Rain)
Water in Vapor Form (Steam)
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In this article, we shall be discussing in detail the concepts of forms of water.
Water in Solid Form
On earth, water is found in solid form as ice caps, glaciers, snow, etc. a very small quantity of water is present in the form of solid water on earth. The solid form of water accounts for only approximately 2% of total water. Glaciers contain almost 68% of freshwater which makes them the main source of usable water. Although most of the glacial lakes are in very inhospitable regions.
Water in Liquid Form
A large portion of the total water on earth is present in liquid form. Oceans, seas, lakes, rivers, rain, and groundwater are the main source of the liquid form of water. Oceans contain 96.5% of the total liquid form of water. Water present in oceans and seas is very saline in nature. This is the reason it is not of much use for human beings. On average 1kg of seawater contains 34 grams of salts. Different lakes, rivers contain freshwater which we can use for drinking purposes. Freshwater is very unevenly distributed on earth. Fresh water in liquid form is present at 87% in lakes, 11% in swamps, and only 2% in rivers. Out of these, river water is highly valuable for human beings.
Water in Vapour Form
Water is present in vapour form in very small quantities. The main sources of vapour form of water are vapour present in the atmosphere, clouds, soil moisture, etc. water is present in vapour form mainly in the troposphere. The amount of vapour in air varies according to the temperature and density of the air. Thus, water is present in mainly three states – solid, liquid, and gas or vapour. All different forms of water or types of water such as tap water, mineral water, spring water, well water, etc. exist in either liquid, solid or gaseous form.
Water Cycle
The water cycle clearly explains the relationship between all three forms of water and the continuous movement of water on earth and its atmosphere. It is also known as the hydrological cycle. Mass of total amount of water remains almost constant on earth although the distribution of water in various sources of the earth depends upon the climate of different regions of the earth.
Learn more about the process water cycle from the below-mentioned diagram -
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Water present in oceans, seas, soil, rivers, lakes, and plants evaporates by the heat of the sun. Due to the lower temperature of the atmosphere of the earth water vapor condenses and forms water droplets. These water droplets get combined due to hydrogen bonding between water molecules and become heavier. Due to heavy water content in clouds precipitation occurs. Which results in rain or snow. Rainwater flows on earth and goes into seas, oceans, lakes, rivers, soil, etc. Plants use water for photosynthesis and transpiration takes place in them. Groundwater also gets replenished by rainwater.
This was brief about different forms of water and their interconnection through the water cycle. If you want to know the chemical aspect of water and its different forms then register yourself on Vedantu or download the Vedantu learning app for classes 6-10, IIT JEE, and NEET.
FAQs on Forms of Water: Solid, Liquid, and Vapor
1. What are the three common forms, or states, of water found on Earth?
The three common forms of water are solid, liquid, and gas. These states are determined by temperature and pressure.
Solid: Below 0°C (32°F), water becomes ice. Its molecules are locked in a fixed, crystalline structure.
Liquid: Between 0°C and 100°C (212°F), water is in its liquid form, which we commonly call water. Its molecules can flow and move past one another.
Gas: Above 100°C, water turns into a gas called water vapour or steam. Its molecules are far apart and move rapidly and randomly.
2. How do water molecules behave differently in ice, liquid water, and water vapour?
The behaviour of water molecules changes significantly with the state, primarily due to the amount of kinetic energy they possess.
In ice (solid), molecules have low energy. They are held in a rigid, hexagonal crystal lattice by strong hydrogen bonds and can only vibrate in their fixed positions.
In liquid water, molecules have more energy. They can overcome some of the rigid bonds, allowing them to slide past each other, giving water its fluid properties.
In water vapour (gas), molecules have very high energy. They move so fast that they completely break free from the bonds holding them together, spreading out to fill any available space.
3. What are the scientific terms for the processes when water changes its form?
The transitions between the states of water have specific names:
Melting: The process of changing from solid (ice) to liquid.
Freezing: The process of changing from liquid to solid (ice).
Evaporation/Boiling (Vaporisation): The process of changing from liquid to gas (water vapour).
Condensation: The process of changing from gas (water vapour) back to liquid.
Sublimation: The process where solid (ice) turns directly into gas (water vapour) without becoming a liquid first.
4. Why does ice float on liquid water?
Ice floats because it is about 9% less dense than liquid water. This is an unusual property for a substance. When water freezes, its molecules arrange themselves into a highly ordered, open crystalline structure (a hexagonal lattice). This structure takes up more space than the more randomly arranged molecules in liquid water, making the ice less dense and causing it to float. This property is crucial for aquatic life in cold climates, as the floating ice insulates the water below, preventing it from freezing solid.
5. What is the difference between evaporation and boiling?
Both evaporation and boiling are processes of vaporisation (liquid to gas), but they occur under different conditions.
Evaporation is a surface phenomenon that can happen at any temperature below the boiling point. Only the molecules at the surface with enough energy escape into the air.
Boiling is a bulk phenomenon that occurs at a specific temperature, the boiling point (100°C for water at sea level). Bubbles of vapour form throughout the entire liquid, not just at the surface, and rise to escape.
6. What are some real-world examples of water in its solid form?
Besides the ice cubes in a drink, solid water is found in many forms in nature and industry. Key examples include:
Glaciers and Ice Sheets: Massive bodies of ice covering land, primarily in polar regions.
Snow: Precipitation composed of ice crystals.
Hail: Pellets of ice that fall during storms.
Frost: Ice crystals that form on surfaces when the temperature drops below freezing.
Food Preservation: Ice is widely used to keep perishable products like fish and meat cold during transport and storage.
7. How is freshwater on Earth distributed among its solid, liquid, and gas forms?
While Earth is 71% water, most of it is saltwater. The small amount of freshwater is distributed unevenly across its three states:
The vast majority of freshwater is in its solid form. About 68.7% is locked up in ice caps and glaciers.
A significant portion exists in liquid form as groundwater (about 30.1%) and in lakes, rivers, and swamps (a very small percentage).
A tiny fraction exists in its gaseous form as water vapour in the atmosphere (about 0.04% of freshwater).
8. Can water exist in more than just three states?
Yes, while solid, liquid, and gas are the three states we experience in daily life, water can exist in other forms under extreme conditions. Scientists have identified over a dozen different types of ice (polymorphs) that form under very high pressures. Additionally, at extremely high temperatures and pressures, water can become a supercritical fluid, a state that has properties of both a liquid and a gas. However, for CBSE/NCERT syllabus purposes, solid, liquid, and gas are the three primary forms to know.
