Which of the following is known as alkaline earth metal?
Magnesium
Understanding Alkaline Earth Metals
The question asks to identify which of the given options is known as an alkaline earth metal. Alkaline earth metals are a series of chemical elements found in Group 2 of the periodic table. These elements have similar properties: they are shiny, silvery-white, somewhat reactive metals at standard temperature and pressure. They readily lose their two outermost s-shell electrons to form cations with a +2 charge.
Common alkaline earth metals include:
- Beryllium (Be)
- Magnesium (Mg)
- Calcium (Ca)
- Strontium (Sr)
- Barium (Ba)
- Radium (Ra)
Analyzing the Given Options
Let's examine each option provided in the question:
- Copper (Cu): Copper is a transition metal, located in Group 11 of the periodic table. It is not an alkaline earth metal.
- Platinum (Pt): Platinum is also a transition metal, located in Group 10 of the periodic table. It is known as a noble metal due to its low reactivity. It is not an alkaline earth metal.
- Magnesium (Mg): Magnesium is an element with atomic number 12. It is located in Group 2, Period 3 of the periodic table. Elements in Group 2 are classified as alkaline earth metals. Therefore, Magnesium is an alkaline earth metal.
- Cobalt (Co): Cobalt is a transition metal, located in Group 9 of the periodic table. It is not an alkaline earth metal.
Identifying the Alkaline Earth Metal
Based on the classification of elements in the periodic table, Magnesium (Mg) is the element that belongs to the group of alkaline earth metals.
| Element | Symbol | Group in Periodic Table | Classification |
|---|---|---|---|
| Copper | Cu | Group 11 | Transition Metal |
| Platinum | Pt | Group 10 | Transition Metal |
| Magnesium | Mg | Group 2 | Alkaline Earth Metal |
| Cobalt | Co | Group 9 | Transition Metal |
Therefore, Magnesium is the correct answer as it is an alkaline earth metal.
Revision Table: Key Concepts
| Term | Definition/Description | Periodic Table Location |
|---|---|---|
| Alkaline Earth Metals | Reactive metals with +2 charge tendency | Group 2 |
| Transition Metals | Elements with incomplete d-subshells (or forming cations with incomplete d-subshells) | Groups 3-12 |
Additional Information on Alkaline Earth Metals
Alkaline earth metals are less reactive than alkali metals (Group 1) but more reactive than many other metal groups. Their reactivity increases down the group. They form strong basic oxides and hydroxides, hence the term "alkaline". They are found abundantly in the Earth's crust, often in the form of minerals.
- Magnesium is important in biological systems and lightweight alloys.
- Calcium is essential for bones and teeth.
- Beryllium is used in alloys and nuclear reactors.
- Barium is used in medical imaging (barium meals).
Understanding the periodic table and the properties of different element groups is fundamental in chemistry.
Important Questions from Classification of Elements and Periodicity in Properties
- Which one of the following is the correct order of the valencies of elements Ne, Si, N and Mg?
The elements of the groups 3 to 12 are called _______ elements or transition elements.
How many electrons are there in the outermost shell of a group 16 element?
What is the chemical symbol of magnesium?
Identify the correct chemical formula of chloroform.
