In this section you will learn about classification of matter on the basis of atom, element, compound, substance etc.
MOVING IN INNER CONCEPT OF ELECTRICITY
In this you will see classification of matter with its smallest unit.
Everything that has mass and occupies space is Matter. We know three states of matter that are solid, liquid and gas. For example gold, wood, ice, water, milk, honey, coffee, air, oxygen, water vapour etc.
Now we can see in chart above, matter is divided (classified) into two categories that are
- Substance &
A substance is simply a pure form of matter. Substance is made up of elements or compounds. Molecules (Atoms can join together – they form bonds together – to make Molecules) of elements or compounds both make substances.
Element are copper (Cu), gold (Au), calcium (Ca), sodium (Na), oxygen(O), carbon (C) etc.
Compounds are water (hydrogen oxide) (H2O), sodium chloride (common salt or table salt) (NaCl), carbon dioxide gas (CO2), oxygen gas(O2) etc.
Pure substances can be further divided into two sub-categories: elements and compounds.
Many atoms of the same type bond together to form an element. Elements are the simplest form of matter. There are 118 elements listed on the periodic table, out of which 94 occur naturally on earth and rest 24 were artificially created .
Examples of elements that are naturally present: carbon (C), hydrogen (H), oxygen (O), sodium (Na), gold (Au), silver (Ag), calcium (Ca) etc.
Example of elements that are artificially created: technetium Tc(atomic number Z = 43), promethium Pm (Z = 61), neptunium Np (93) etc.
Compounds, on the other hand, are made up of two or more different elements held together by chemical bonds and functioning as a unit. However, compounds are also pure substances, they differ from elements because compounds can be broken down into simplest elements (the elements that make up the compound). Compounds also have a specific chemical formula like NaCl, or C6H12O6? If yes, then it is a compound.
Examples of compounds are carbon dioxide (CO2), rust (Fe2O3), water (hydrogen oxide) (H2O), sodium chloride (common salt or table salt) (NaCl), carbon dioxide gas (CO2), oxygen gas (O2) etc.
A mixture is made when two or more substances combine, but they are not combined chemically. The components of a mixture can be easily separated, so the components of a mixture can be easily separated and is therefore said to be impure.
Examples of mixtures are
- Honey and tea.
- Milk and chocolate.
- Coffee and sugar.
- Cake ingredients.
- Smog (smoke + fog)
- Mud puddle (dirt + water)
- Air (oxygen + nitrogen + other gasses)
- Atom (nucleus + electrons)
- Cement (sand + water + gravel)
- Dirty snow (water + dirt)
- Ocean water (water + salt)
Atom are the smallest unit of matter. An atom composed of three subatomic particles that are electron, proton and neutron. The neutrons and the protons make the center of an atom called nucleus. And the electrons move around the nucleus in orbits (shell).
Electrons are negatively charged particles, Protons are positively charged particles & Neutron is neutral means no charge is present
Neutron “ ”
Things to be note:
- As we know nucleus is composed of proton and neutron, and protons are positively charged and neutrons have no charge so overall we can say nucleus is positively charged.
- The strong nuclear force between neutrons and protons stick them together to form a nucleus.
- The negatively charged electrons are orbiting around the nucleus because of the electrostatic force of attraction present between electrons and protons.
If the numbers of electrons are equal to the number of protons in an atom then the overall charge of the atom is neutral.
And if the numbers of electrons are more than the numbers of protons in an atom then the atom is negatively charged.
If the numbers of electrons are less than the numbers of protons in an atom then the atom is positively charged.
The charge of proton and electron measures in coulombs, denoted by “C”.
Charge of a electron = – 1.602 × 10-19 Coulombs (C)
Charge of a proton = + 1.602 × 10-19 Coulombs (C).
Both the charges are equal in magnitude but have different signs.
THIS IS ALL FOR CLASSIFICATION OF MATTER. NEXT YOU WILL LEARN ORBIT & ENERGY LEVEL OF ORBITS
ATOM, ORBITS AND ENERGY LEVELS
HOW ELECTRICITY IS GENERATED