Advertisements
Advertisements
Question
An element has its electron configuration as 2,8,8,2. Now answer the following questions.
a) What is the atomic number of this element?
b) What is the group of this element?
c) To which period does this element belong?
Advertisements
Solution
a) The atomic number of this element is 20.
b) The group of this element 2.
c) This element belongs to fourth period.
APPEARS IN
RELATED QUESTIONS
In the extraction of aluminium: Name the process of concentration of bauxite.
Name the most abundant metal in the earth’s crust.
A zinc ore on heating in air forms sulphur dioxide. Describe briefly any two stages involved in the conversion of this concentrated ore into zinc metal.
Define the term ore.
Name two metals which are found in nature mainly in the free state (as metallic elements).
Give the name of one ore of iron. Which iron compound is present in this ore? Write its chemical formula.
Which of the following is an ore of mercury metal?
An element A which is a part of common salt and kept under kerosene reacts with another element B of atomic number 17 to give a product C. When an aqueous solution of product C is electrolysed then a compound D is formed and two gases are liberated.
- What are A and B?
- Identify C and D.
- What will be the action of C on litmus solution? Why?
- State whether element B is a solid, liquid or gas at room temperature.
- Write formula of the compound formed when element B reacts with an element E having atomic number 5.
When an object made of metal A is kept in air for a considerable time, it loses its shine and becomes almost black due to the formation of a layer of substance B. When an object made of another metal C is kept in damp air for a considerable time, it gets covered with a green layer of substance D. Metal A is the best conductor of electricity whereas metal C is the next best conductor of electricity.
- What is metal А?
- What is metal C?
- Name the substance B.
- Name the substance D.
- What type of chemical can be used to remove the green layer from metal C and clean it? Why?
Give the principles of electromagnetic separation.
Give the chemical formula of :
Sodium aluminate
Name the following:
Name two metals always find in combined state.
What is passive iron?
Which one of the following is not true of metal :
Metals are malleable and ductile
choose the most appropriate term to match the given description.
Heating of the ore in the absence of air to high temperature
In Electrolytic reduction of alumina, Anode : _______ : : Cathode : Graphite lining
Write the molecular formulae of the following compound.
Cryolite
Explain the following reaction with the balanced equation.
Zinc sulphide is heated strongly in excess of air
Why should the metal sulphides and carbonates be converted to metal oxides in the process of extraction of metal from them?
