Advertisements
Advertisements
Question
Give reasons
Gold is mixed with copper and nickel.
Advertisements
Solution
Pure gold is a very soft metal. It cannot be moulded into ornaments so it is mixed with copper and nickel so that it becomes harder and bit cheaper also.
APPEARS IN
RELATED QUESTIONS
Mark ‘T’ if the statement is true and ‘F’ if it is false.
Generally, non-metals react with acids. ( )
Saloni took a piece of burning charcoal and collected the gas evolved in a test tube.
(a) How will she find the nature of the gas?
(b) Write down word equations of all the reactions taking place in this process.
Give a reason for the following:
Alkali metals are good reducing agents.
State five uses of metals.
State one use of the following metal:
Gold
Explain how, a reduction reaction of aluminium can be used for welding cracked machine parts of iron. Write a chemical equation for the reaction involved.
A metal with melting point less than 50°C is
Fill in the blank spaces by choosing the correct words from the given list.
List: amalgam, chlorine, gallium, sodium chloride, silver chloride
Salt of silver, such as ________ is used for making photographic films.
State two important uses of following metal.
Uses of copper
State the position of the following in the periodic table:
Iron and zinc
With reference to the following metals state their use in daily life metal:
iron
With reference to the following metal state its use in daily life:
Magnesium
State a specific reason for using copper in electrical cables
Name the following:
A halogen which is a solid at room temperature.
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.
Complete the following flowchart.

In the following figure, you find that the bulb glows when an iron nail is placed between two ends of wire. Complete the following sentences on the basis of this fact.

- ______ is a metal.
- Metals are good ______ of electricity.
The liquid metal at room temperature ______.
Sodium is a hard metal.
