What are Alkaline Earth Metals
The family of chemical elements called alkaline earth metals includes beryllium, magnesium, calcium, strontium, barium and radium. These chemical elements occupy the second column of the periodic table. The designation of the earth for these elements came from the Middle Ages when chemists referred to several substances that were insoluble in water and unchanged by fire, such as earth.
Alkaline earth metals are lustrous, soft or semi-soft metals insoluble in water. They are generally harder and less reactive than metals in group IA, such as sodium, and are softer and more reactive than metals in group IIIA, such as aluminium. When they combine with oxides (molecules of oxygen and another element), they form some of the most common minerals on Earth, with various uses in industry, medicine, and consumer goods. Some compounds give off a lot of light when heated, making them a key element in fireworks.
Alkaline Earth Metal
Properties of Alkaline Earth Metals
The presence of alkaline earth metals is silvery white.
These are soft metals.
Their boiling point is higher than that of alkali metals.
These elements can be tested by flame test as they give different colours when exposed to flame.
These metals can conduct electricity.
Alkaline earth metals have high electronegativity so they are electropositive.
Magnesium is an alkaline earth metal that does not give any colours when exposed to flame.
Alkaline earth metals are good conductors of heat.
Types of Alkaline Earth Metals
How are Alkaline Earth Metals Used?
Uses of Alkaline Earth Metals in daily life. Some of these uses are given below:
Magnesium is used to make a variety of alloys.
Magnesium is also used in medicines to take antacids.
Magnesium Alkaline Earth Metal
Radium is used to treat cancer.
Calcium is used in the extraction of various elements.
Calcium is used to produce calcium carbonate, which is used in various products such as marble, chalk, limestone, etc.
Plaster of Paris is also made from calcium and is used in decoration, designing and fireproofing.
3 Useful Applications of Alkaline Earth Metals
Hydrogen gas is used for many purposes. Hydrogen gas is obtained from the reaction of alkaline earth metals with acids.
Alkaline earth metals are used in making electrochemical and photoelectric cells.
Alloys of magnesium are used to manufacture aircraft and fighter aircraft.
Solved Questions
Which alkali earth metal is used to treat cancer?
Ans: Radium is used to treat cancer.
Write two properties of alkali earth metals.
Ans: Two uses of alkali earth metals are:
They have a high boiling point.
They can conduct electricity.
Write two uses of alkali earth metals.
Ans: Two uses of alkali earth metals are:
Calcium is used to make calcium carbonate which is used to make various products like chalk, marble, limestone etc.
Alloys of magnesium are used in the manufacture of aircraft and fighter aircraft.
Learning by Doing
Write True or False.
Calcium is not an Alkali Earth metal.
Radium is an Alkali Earth metal.
Alkaline earth metals are bad conductors of heat.
Alkali Earth metals are soft metals.
Summary
This chapter helped us to understand the basics of Alkali Earth Metals. We have studied many things about it, like its properties and uses, which will help us to gain some practical knowledge and understanding. It is a very important topic in Chemistry. This helps us to know the chemical elements of alkali earth metals.
FAQs on Uses of Alkaline Earth Metals
1. Mention the medical uses of magnesium.
Medical uses of magnesium:
Magnesium oxide is used in treating constipation.
Magnesium is also used as anaesthesia when salts of magnesium are injected into the human body.
2. Why does radium have little biological significance?
Radium is radioactive, and due to its toxicity, radium has no biological use. In the medical field, it is used only for producing radon gas which is used in the treatment of cancer.
3. Why does beryllium have different properties from the rest of the group members?
There are mainly two reasons for the different properties of beryllium from its group members:
Size: The atomic size of beryllium is very small compared to other elements in the same group, so it does not follow the same trends as other alkaline earth metals.
Atomic Number: Since beryllium has an atomic number of 4, its coordination number cannot exceed 4, while other members of the same group can have a coordination number of 6.