How do solids liquids and gases differ at the molecular level

The gas particles have big distances between them. Solid — In a solid, the attractive forces keep the particles together tightly enough so that the particles do not move past each other. Their vibration is related to their kinetic energy. In the solid the particles vibrate in place. Liquid — In a liquid, particles will flow or glide over one another, but stay toward the bottom of the container.

The state of matter can change when the temperature changes. Generally, as the temperature rises, matter moves to a more active state. For example, water vapour gas can condense and become a drop of water. If you put that drop in the freezer, it would become a solid. No matter what phase it is in, it is always water — two atoms of hydrogen attached to one atom of oxygen H 2 0.

In a liquid, the atoms and molecules are loosely bonded. They move around but stay close together. The atoms and molecules move freely and spread apart from one another. States of matter can be more than just your average solids, liquids and gases! Objectives Differentiate between the three main states of matter. Describe different properties of matter. Thus, liquids are denser than gases making them difficult to compress. A liquid also has a definite volume and assumes the shape of the container.

Despite stronger attractive forces, molecules in liquids can still move freely about one another, and so the liquids can flow or be poured.

When liquids are further cooled, the kinetic energy reduces to a point where the particles almost stop moving due to the strong intermolecular forces and can only vibrate at their fixed position. At this point, molecules transform into a three-dimensional conformation state called solids. In any solid, molecules are densely packed, leaving almost no empty space around them. Thus, solids are incompressible, having a definite volume and shape. Particles in a solid are tightly packed together fixed shape and often arranged in a regular pattern; in a liquid, they are close together with no regular arrangement no fixed shape ; in a gas, they are far apart with no regular arrangement no fixed shape.

Particles in a solid vibrate about fixed positions cannot flow and do not generally move in relation to one another; in a liquid, they move past each other can flow but remain in essentially constant contact; in a gas, they move independently of one another can flow and expand except when they collide.

The differences in the properties of a solid, liquid, or gas reflect the strengths of the attractive forces between the atoms, molecules, or ions that make up each phase. The phase in which a substance exists depends on the relative extents of its intermolecular forces IMFs - electrostatic forces of attraction existing between the atoms and molecules of a substance - and the kinetic energies KE of its molecules. For example, in a liquid, attractive intermolecular forces hold the molecules in contact, although they still have sufficient KE to move past each other.

Due to this, liquids flow and take the shape of their container. According to kinetic-molecular theory KMT , the temperature of a substance is proportional to the average KE of its particles.

Changing the average kinetic energy temperature induces changes in the physical state along with associated changes in intermolecular forces. For example, when gaseous water is cooled sufficiently, or the average kinetic energy of molecules is reduced, the increased attraction between H 2 O molecules will be capable of holding them together when they come into contact with each other; the gas condenses, forming liquid H 2 O.

When liquid H 2 O is further cooled, the attractive forces become stronger, and water freezes to form solid ice. In cases where the temperatures are not too high, gases may be liquefied by compression high pressure. Gases exhibit very weak attractive forces due to which the particles are spread apart at large distances.

The increased pressure brings the molecules of a gas closer together, such that the attractions between the molecules become strong relative to their KE. Consequently, they form liquids. Butane, C 4 H 10 , is the fuel used in disposable lighters and is a gas at standard temperature and pressure. Moreover, if the temperature of a liquid becomes sufficiently low or the pressure on the liquid becomes sufficiently high, the molecules of the liquid no longer have enough KE to overcome the IMF between them and a solid forms.

Unlike ice or water, water vapour is invisible. We exhale water vapour whenever we breathe out. We cannot see the water vapour as we exhale, but if we hold our eyeglasses or smartphone to our mouths, we can see the water vapour condensing becoming liquid on these objects. One state is plasma, which naturally occurs in lightning, and we create it in fluorescent light bulbs and plasma TVs. Another state of matter is Bose-Einstein condensate, but this state only occurs with super-low temperatures.

Science knowledge changes as we discover new evidence. Technology helps us find this evidence. To learn more about plasmas and Bose-Einstein condensates, read these two articles that look at these science ideas and concepts.

States of matter Matter in our world. Use the interactive Moisture sources in our homes to find out how moisture enters our homes and how we can minimise and remove it. Visit the Scholastic website for simple states of matter activities. These include a video, song and quiz. Add to collection.

Nature of science Science knowledge changes as we discover new evidence.