Advertisements
Advertisements
प्रश्न
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
उत्तर
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
संबंधित प्रश्न
Give reasons.
Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset, but after a futile argument, the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?
Write the steps involved in the extraction of pure metals in the middle of the activity series from their carbonate ores.
Name the gas in air which tarnishes silver articles slowly.
Explain why, carbon cannot reduce oxides of sodium or magnesium.
Which one of the methods given in column I is applied for the extraction of each of the metals given in column II:
| Column I | Column II |
| Electrolytic reduction | Aluminium |
| Reduction with Carbon | Zinc |
| Reduction with Aluminium | Sodium |
| Iron | |
| Manganese | |
| Tin |
Explain giving one example, how highly reactive metals (which are high up in the reactivity series) are extracted.
Explain givem equation, what happens when a mixture of Cu2O and Cu2S is heated?
Name the metal which is extracted from haematite ore.
Zinc blende ore can be converted into zinc oxide by the process of:
(a) roasting
(b) hydrogenation
(c) chlorination
(d) calcination
Which metal can be extracted from the following ore?
Calamine
Give reasons, why aluminum is used in:
In making ships
Answer the following questions based on the extraction of aluminium from alumina by Hall - Heroult’s Process :
Name the electrode, from which aluminium collected.
Complete the incomplete statement with missing word:
Non-metals form acidic oxides while metals form ______.
Correct the following statement :
Copper reacts with nitric acid to produce nitrogen dioxide.
Draw a well-labelled diagram of extraction of Aluminium. Write the anode reaction in electrolytic reduction of Alumina.
Write the molecular formulae of the following compound.
Sodium aluminate
Read the following passage and answer the questions.
According to the reactivity series, zinc is more reactive than iron, iron is more reactive than silver. During study of this, a student dipped the iron nails in silver nitrate solution.
- What is reactivity series?
- What will happen when iron nails are dipped in silver nitrate solution?
- Which type of reaction happens when iron metal reacts with silver nitrate solution?
- What will happen if a zinc rod is used instead of iron nail?
Observe the figure and answer the following.
- Write the name of the method.
- What is used as anode and cathode in this method?
- Write the molecular formula and use of cryolite.
- Write anode reaction.
- Write cathode reaction.
Oxides of moderately reactive metals like Zinc, Iron, Nickel, Tin, Copper, etc. are reduced by using:
