Matter

Matter

Matter is anything, such as a solid, liquid or gas that has weight (mass) and occupies space. For anything to occupy space, it must have volume. Thinking about it, everything on earth has weight and takes up space, and that means everything on earth is matter.

Mass is a property of a physical body. It is the measure of an object's resistance to acceleration (a change in its state of motion) when a force is applied.[1] It also determines the strength of its mutual gravitational attraction to other bodies.

Volume is the quantity of three-dimensional space occupied by a liquid, solid, or gas.

Density can be the amount of matter in a given volume, also known as mass density.

What are solids?

Solids are simply hard substances, and they are hard because of how their molecules are packed together. Examples include rock, chalk, sugar, a piece of wood, plastic, steel or nail. They are all solids at room temperature. They can come in all sizes, shapes and forms.

What is a liquid?

The particles in liquids are not as closely bonded, arranged and fixed in place as in solids. The particles in liquid can flow freely and can mix with particles from other liquids. Liquids have their atoms close together, so they are not very easy to compress.

What are gases?

Gas is everywhere, and it surrounds us. The air around us is a kind of gas. The atmosphere surrounding the earth is a gas too. Helium, Oxygen, Carbon dioxide and water vapour are all gases.

The particles in gases are very different from that of solids and liquids.

In gases, the particles are far apart from each other and arranged in a random way. The particles also move quickly in all directions. Gases can fill up any container of any shape and size. Gases can be compressed or squashed because the molecules are far from each other. When gas is compressed, the gas molecules move from an area of high pressure to low pressure.

What is a Physical Change?

In a physical change, the internal make-up of the object (molecules) stays the same, even after the change — only its form changes. The resulting element can be reversed into the object before. Changes that can be reversed are called a Reversible Change.

In a physical change, the state, shape or size of the object is changed. Pressure, temperature or motion can bring about a physical change.
Change in state:
Put some water into a plastic cup and place it in the freezer. After sometime the water changes into ice, right?

The water moved from a liquid state to a solid state. With a bit of heat energy, the ice will melt back into water. Note that the stuff that water is made up of, hydrogen oxygen, did not change, but its’ state changed from liquid to ice and back to liquid.

What is a Physical Change?

Physical properties are properties of an element or compound that can be observed without a chemical reaction of the substance. Density and electrical conductivity are examples of physical properties.

In a physical change, the substances are not altered chemically. No new products are formed. Chemical bonds are not broken in a physical change

A physical change can affect the size, shape or color of a substance but does not affect its composition. The substances may be changed to another phase (i.e. gas, liquid, solid) or separated or combined.

Examples:

when ice melts

when sulfur is mixed with iron filings.

breaking a glass

dissolving sugar in water