GROUP 1 ELEMENTS
- The elements in Group 1 are known as alkali metals.
- Group 1 elements form compounds which are widely used in different field.
- These elements include lithium, sodium, potassium, rubidium, caesium and francium.
- Some of uses of Group 1 elements:
•Sodium carbonate, Na2CO3 : Soda lime glass
•Lithium : Batteries
•Potassium nitrate, KNO3 : Fertiliser
•Lithium carbonate, Li2CO3 : Used to make tube in television
- Group 1 elements form compounds which are widely used in different field.
- These elements include lithium, sodium, potassium, rubidium, caesium and francium.
- Some of uses of Group 1 elements:
•Sodium carbonate, Na2CO3 : Soda lime glass
•Lithium : Batteries
•Potassium nitrate, KNO3 : Fertiliser
•Lithium carbonate, Li2CO3 : Used to make tube in television
PHYSICAL PROPERTIES
- Lithium, sodium and potassium are metals but they have some unusual physical properties. Let find out these properties.
- Group 1 element are soft metals with low densities and low melting points as compared to other metals such as iron and copper.
- In addition, they have silvery and shiny surfaces. They are also good conductors of heat and electricity.
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- Some of these physical properties, however, change gradually when going down Group 1. Let us study figure below.
- Lithium, sodium and potassium are metals but they have some unusual physical properties. Let find out these properties.
- Group 1 element are soft metals with low densities and low melting points as compared to other metals such as iron and copper.
- In addition, they have silvery and shiny surfaces. They are also good conductors of heat and electricity.
-
- Some of these physical properties, however, change gradually when going down Group 1. Let us study figure below.
CHEMICAL PROPERTIES
- Lithium, sodium and potassium have similar chemical properties but differ in reactivity.
- Alkali metals react vigorously with water to produce alkaline metal hydroxide solution and hydrogen gas, H2 . For example,
- Lithium, sodium and potassium have similar chemical properties but differ in reactivity.
- Alkali metals react vigorously with water to produce alkaline metal hydroxide solution and hydrogen gas, H2 . For example,
- Alkali metals burn in oxygen gas, O2 rapidly to produce white solid metal oxides. For example,
- The alkali metals burn more vigorously from lithium to potassium.
- The solid metals oxides formed can dissolve in water to form alkaline metal hydroxide solution.
- The solid metals oxides formed can dissolve in water to form alkaline metal hydroxide solution.
- Alkali metals burn in chlorine gas, Cl2 to form white solid metal chlorides. For example,
- Alkali metals burn in bromine gas, Br2 to form metal bromides. For example,
- Lithium, sodium and potassium have similar chemical properties because alkali metals have one electron in their outermost occupied shells.
- Each of them react by donating one electron from outermost occupied shells to form an ion with a charge of +1, thus achieving the stable electron arrangement of the atom of noble gas.
- When going down Group 1, the single valence electron in the outermost occupied shells becomes further away from the nucleus.
- Hence, the attraction between nucleus and the valence electron becomes weaker.
- Therefore, it is easier for the atom to donate the single valence electron to achieve the stable electron arrangement of the atom of noble gas.
SAFETY PRECAUTION
- All alkali metals are extremely reactive. Lithium, sodium and potassium must be stored in paraffin oil bottle.
- Do not hold alkali metals with your bare hands. Use forceps to take them and remember to wear safety goggles and gloves.
- When conducting experiments, make sure that only a small piece of alkali metal is used.
- Each of them react by donating one electron from outermost occupied shells to form an ion with a charge of +1, thus achieving the stable electron arrangement of the atom of noble gas.
- When going down Group 1, the single valence electron in the outermost occupied shells becomes further away from the nucleus.
- Hence, the attraction between nucleus and the valence electron becomes weaker.
- Therefore, it is easier for the atom to donate the single valence electron to achieve the stable electron arrangement of the atom of noble gas.
SAFETY PRECAUTION
- All alkali metals are extremely reactive. Lithium, sodium and potassium must be stored in paraffin oil bottle.
- Do not hold alkali metals with your bare hands. Use forceps to take them and remember to wear safety goggles and gloves.
- When conducting experiments, make sure that only a small piece of alkali metal is used.