Advertisements
Advertisements
प्रश्न
Give scientific reasons.
Silver amalgam is used for filling dental cavities.
Advertisements
उत्तर
Because silver amalgam melts at low temperatures and may easily fill cavities, it is used to fill cavities.
APPEARS IN
संबंधित प्रश्न
Two methods by which rusting of iron can be prevented are ______ and ______.
Explain how painting of an iron gate prevents it from rusting.
Explain why Iron sheets are coated with zinc during galvanization.
What type of chemical reaction is involved in the corrosion of iron?
Explain why, iron sheets are coated with zinc.
Fill in the following blanks with suitable words:
Tiffin boxes are electroplated with .............. but car bumpers are electroplated with ............... to protect them from rusting.
Fill in the following blanks with suitable words:
............ and .............. are necessary for the rusting of iron.
What is meant by 'rusting of iron'? With the help of labelled diagrams, describe an activity to find out the conditions under which iron rusts.
Name five methods of preventing rusting of iron.
What are the constituents of stainless steel?
What are the special properties of stainless steel?
Name an alloy of copper. State its chemical composition and any one use.
Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.
If copper is kept exposed to damp air for a considerable time, it gets a green coating on its surface. This is due to the formation of:
(a) hydrated copper sulphate
(b) copper oxide
(c) basic copper carbonate
(d) copper nitrate
Four metals P, Q, R and S are all obtained by the reduction of their oxides with carbon. Metal P is used to form a thin layer over the sheets of metal S to prevent its corrosion. Metal Q is used for electroplating tiffin boxes made of metal S whereas metal R is used in making car batteries. Metals Q and R form an alloy called solder. What are metals P, Q, R and S? How have you arrived at this conclusion?
Find the odd man out:
What are the adverse effects of corrosion?
Write three methods of preventing rusting of iron.
Give reason.
A wooden article should be polished.
State whether the statement given below is true or false. If false write the correct statement.
Either oxygen or moisture is essential for rusting.
When one of the metals in an alloy is mercury the alloy is called _______.
Pressure cooker : Anodizing : : Silver plated spoons : _______
Write the name.
An alloy of copper and tin-
Write scientific reason.
Anodization method is useful for prevention of the corrosion of the aluminium.
Explain concept with example/explain with the help of a balanced equation.
Corrosion
Write a molecular formula for rust.
What is rust?
Give the equation for the formation of rust.
Copper objects lose their shine and form green coating of ____________.
The diagram shows the reaction between metal and dil. acid.
What is the reason for different behaviour of Mg in test tube B?
Alloys are homogeneous mixtures of a metal with a metal or non-metal. Which among the following alloys contain non-metal as one of its constituents?
State whether the following statement is true or false:
Ships suffer a lot of damage though they are painted.
Explain the following:
Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate.
Give an example of a chemical reaction for the following situation:
Sound is produced
Describe two changes that are harmful. Explain why you consider them harmful. How can you prevent them?
