Matter and its Structure

What is Matter?

Everything around us is Matter – it is the substance of which all things are made. Anything which occupies space is matter – it has a Volume. And it has a certain quantity in every object – called its Mass. So, any substance which has mass and takes up space by having volume is Matter. Our atmosphere, the earth, the Sun, planets, and stars, the animals, trees, and marine life, even our own bodies, all constitute matter. Put your science knowledge to the test with this challenging 6th Grade Science Worksheet! Read each question carefully and choose the response that you feel is correct.

What are the Properties of Matter?

How do we recognize the many varieties of matter? Based on their special characteristics, or properties!The matter has physical and chemical properties.

Physical Properties are those which we can recognize by our senses – sight, sound, smell, touch, taste. For example, we recognize gold by its color, sugar by its taste, and gasoline by its smell.

Chemical Properties are based on how one kind of matter acts when it undergoes a chemical change. For example, iron rusts when it comes in contact with moist air – this is a chemical property of iron. Doubts? A 6th-grade science tutor can help.

What is Matter made of?

The tiniest bit of all matter is the Atom. The tiniest bit of gold is one atom of gold. The tiniest bit of oxygen, of mercury, indeed of every solid, liquid, and gas in the universe, is one atom of that matter. It is the most basic unit of all matter. All matter is made of atoms.

Atoms are made up of even smaller things, called Subatomic Particles! There are three subatomic particles in every atom. All atoms of the same matter (gold or mercury or oxygen) have the same numbers of these subatomic particles. These particles are –

1. Protons
2. Neutrons
3. Electrons

What are the Elements?

All atoms of the same kind make up an Element –

• All atoms of oxygen make up the Gaseous Element known as oxygen
• All atoms of gold make up the Solid Element known as gold
• All atoms of mercury make up the Liquid Element known as mercury

So, an elementcan be solid, liquid or gas. An element is the most basic chemical substance. It is a pure substance which cannot be further broken down by any chemical means. In chemical terms, all the atoms of an element have exactly the same number of protons in their nuclei. All the known elements in the universe are arranged in thePeriodic Table.

What are Molecules?

Atoms of the same element, or of different elements, combine to form Molecules –

• Two oxygen atoms combine to form an oxygen molecule
• Two hydrogen atoms combine to form a hydrogen molecule
• Two hydrogen atoms combine with one oxygen atom to form a liquid molecule: water
• Two oxygen atoms combine with one carbon atom to form a gas molecule: carbon dioxide
• One sodium atom combines with one chlorine atom to form a solid molecule: salt

A molecule retains all the properties of the substance from which it is obtained. Further division of a molecule yields only atoms of the individual elements.

What are Compounds?

When atoms of different elements combine chemically in a fixed ratio, the result has named a Compound. In the examples above, water is a compound. So are carbon dioxide and salt. Compounds are only created chemically and can only be separated through chemical means. Each compound has its own unique properties, which are different from the properties of the individual elements from which it is made. Compounds may be solids, liquids, or gases.

What are Mixtures?

If two or more elements or compounds are physically mixed together, the result is a mixture.A mixture is not formed through chemical means. Examples of mixtures are –

• Salt dissolved in water to make saltwater
• Coffee with milk
• Air
• Soil
• Vegetable soup

The components of a mixture can be separated by various physical means without the need for any chemical reaction. For example, saltwater can be separated into salt and water simply through evaporation of the water. A mixture may be Homogenous, meaning that the composition is uniform throughout the mixture, or Heterogenous, meaning that the composition is not uniform. In the examples above, saltwater, coffee with milk, and air, are homogeneous mixtures, while soil and vegetable soup are heterogeneous mixtures.

Check Point

1. Which of these are properties of matter?
   1. Mass
   2. Volume
   3. Weight
   4. Smell
   5. All of the above
2. ______ whiz around the nucleus in fixed orbits.
3. All atoms of the same kind make up an ______.
4. The division of a molecule yields only ______ of the individual elements.
5. Soil is an example of a ______ mixture.

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