Advertisements
Advertisements
प्रश्न
Write scientific reason.
Generally the ionic compounds have high melting points.
उत्तर
- Ionic compounds are composed of cations and anions.
- These ions are held together by strong electrostatic forces of attraction.
- Considerable amount of energy is required to break these strong forces of attraction.
Hence, the melting points of ionic compounds are high.
संबंधित प्रश्न
What is an amalgam?
Fill in the following blank with suitable word:
Brass is an alloy of copper and .........
Give reasons
Gold is mixed with copper and nickel.
State two important uses of following metal
Uses of aluminium
State the position of the following in the periodic table:
Alkaline earth metals
Why is hydrogen placed with alkali metals?
Match the alloys given in column I to the uses given in column II :
Column I | Column II |
(i) Duralumin | A. Electrical fuse |
(ii) Solder | B. Surgical instruments |
(iii) Brass | C. Aircraft body |
(iv) Stainless Steel | D. Decorative articles |
Name the following:
The chemical compound responsible for the green deposit on the surface of articles of copper.
Name the following:
A metal used in flexible pipes.
On heating which of the following substances i.e. copper carbonate, zinc carbonate, washing soda, copper sulphate, zinc nitrate, copper nitrate, lead nitrate, ammonium chloride and ammonium dichromate – relate to the reaction given below.
A white crystalline solid which decrepitates on heating leaving a residue which fuses with the glass and evolves two gases one of which is coloured and acidic.
What is ductility?
Can you store pickle in an aluminium utensil? Give reason.
Generally, metals are solid in nature. Which one of the following metals is found in a liquid state at room temperature?
______ is the first scientist who used the term element.
The liquid metal at room temperature ______.
Metals are ______ conductors of heat and electricity.
All gases are ______.
Sodium is a hard metal.
Why are metalloids called semimetals?