Depending on their chemical composition Pure substances can be classified as i) Element ii) Compound
Element:
A Pure substance which are made up of only one kind of atom. (or)
A Pure substance which can not be sub divided into two or more simpler substances by any Chemical means called Element. It is a basic form of matter that cannot be chemically broken downinto simpler substances. And a substance is made up of the atom with same atomic number.
Example: Iron is an element when we break it into pieces as small as possible, But even these small pieces are of iron.
: Gold, iron, Hydrogen, oxygen, Aluminium, nitrogen, copper etc.
Classification of Element
In First chapter we have seen that the Physical state of matter, All Element can be divided in three groups, that is solid, liquid, and gas. Now based on Variations their properties element can be classified following .
a) Metal b) Non Metal c) Metalloids
a) Metal:
Metals are opaque malleable, ductile in nature element that are good conductor Heat and electricity.
Properties of metals:
1) Malleable:
Those metals have ability to form thin sheet by hammering or rolling called Malleable Metals.
Example: Aluminium, Gold, Silver etc
2) Ductile:
Those metals have ability to form in thin wire called Ductile Metals.
Example: copper, aluminium, platinum etc.
3) Sonorous:
Those metals give a sound of ring Bell when we hammer on it called sonorousMetals. Its also called metallic sound.
Example: iron, silver, copper, aluminium etc.
4) Lustrous:
Those metals have the ability to shine
Are called lustrous metals.
Example:Gold, silver, copper etc.
b) Non-Metal:
The Non Metals are opposite of Metals it has poor conductor of heat and electricity.
Properties of Non-Metals:
- Non metals are neither malleable nor ductile.
- Non metals are brittle, Means that they will break if hammer on it.
- Melting point of Non-Metals is very low. Except diamond and graphite.
- Non metals cannot be hammered to form a sheet.
- Non metals exist in all three state of matter – solid, liquid, gaseous.
- Non metals do not allowed to heat and electricity pass through them.
- Most of the metals are insulators.
- Non metals does not have lustrous or shining surface like metals. But actually have dull appearance.
- For example sulphur and phosphorus are solid non metals which are not malleable.
- Non metals generally soft except diamond which is extremely hard .
- Diamond (which is an Allotropic Form of carbon ) is the hardness natural substance.
- Most of the Non metals are not strong they break easily.
C) Metalloids:
Those elements have the properties in between metals and non metals Called Metalloids.
Example: Germanium (Ge), Arsenic (As), Silicon (Si) , Antimony (Sb), and Tellurium (Te), etc.
Properties of Metalloids:
- Metalloids showsome properties of metal and other properties non metals.
- For example they look like metals but brittle like non metals.
- They are neither good conductor of electricity or nor good insulator like non metals.
- Metalloids are generally semi conductors.
- Metalloids having some properties of metallic lustier.
- Metalloids are generally solid at room temperature.
- Metalloids are not malleable and ductile.
Question Answer
1) Explain the elements with example?
Answer:A Pure substance which are made up of only one kind of atom. (or)
A Pure substance which can not be sub divided into two or more simpler substances by any Chemical means called Element. It is a basic form of matter that cannot be chemically broken down into simpler substances. And a substance is made up of the atom with same atomic number.
Example: Iron is an element when we break it into pieces as small as possible, But even these small pieces are of iron.
Example: Gold, iron, Hydrogen, oxygen, Aluminium, nitrogen, copper etc.
2) Write the classification of Elements?
Answer: element can be classified following .
a) Metal b) Non Metal c) Metalloids
a) Metal:
Metals are opaque malleable, ductile in nature element that are good conductor Heat and electricity.
b) Non-Metal:
The Non Metals are opposite of Metals it has poor conductor of heat and electricity .
c) Metalloids:
Those elements have the properties in between metals and non metals Called Metalloids.
Example: Germanium (Ge), Arsenic (As), Silicon (Si) , Antimony (Sb), and Tellurium (Te), etc.
3) Write the properties of Non Metals?
Answer: Properties of Non Metals are following.
- Non metals are neither malleable nor ductile.
- Non metals are brittle, Means that they will break if hammer on it.
- Melting point of Non-Metals is very low. Except diamond and graphite.
- Non metals cannot be hammered to form a sheet.
- Non metals exist in all three state of matter – solid, liquid, gaseous.
- Non metals do not allowed to heat and electricity pass through them.
- Most of the metals are insulators.
- Non metals does not have lustrous or shining surface like metals. But actually have dull appearance.
- For example sulphur and phosphorus are solid non metals which are not malleable.
- Non metals generally soft except diamond which is extremely hard .
- Diamond (which is an Allotropic Form of carbon ) is the hardness natural substance.
- Most of the Non metals are not strong they break easily .
4) Write the properties of metalloids?
Answer: properties of metalloids are following.
- Metalloids show some properties of metal and other properties non metals .
- For example they look like metals but brittle like non metals.
- They are neither good conductor of electricity or nor good insulator like non metals.
- Metalloids are generally semi conductors.
- Metalloids having some properties of metallic lustier.
- Metalloids are generally solid at room temperature.
- Metalloids are not malleable and ductile.
5) Write down difference between Metal and Non Metal?
Answer:
Sr. No. |
Metal | Non Metal |
1. | Metal have high Melting point and boiling Point except gallium and cesium. |
Non Metal have low boiling point and melting point except graphite and diamond. |
2. | ||
3. |
Metals are malleable and ductile. | Non metals neither malleable nor ductile. |
4. | Metals are good conductor of heat and electricity. |
Non metals are generally poor conductor of heat and electricity except graphite. |
5. |
Metals give sonorous sound when hammered on it. | 5.Non Metals doesn’t give sonorous sound when hammered on it. |
6. | Metals are shining lustre. |
Non metals are not lustre except iodine. |