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प्रश्न
What's the solution?
We need to rub salt on a corncob, but only salt crystals are available.
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उत्तर
We can pound salt crystals. Either we can use mortar pestle or we can also crush the crystals of salt in a grinder. Such powdered salt can be easily applied on the corncob.
संबंधित प्रश्न
Select the correct alternative
The molecules can move freely anywhere in
- gases
- liquids
- solids
- none of the above
Fill in the blank :
The state of matter with definite volume and definite shape is called______
Define matter. Give four examples of matter.
Iron powder and sulphur powder were mixed together and divided into two parts A and B. When part A was heated strongly over a burner, then a substance C was formed. The part B was, however, not heated at all. When dilute hydrochloric acid was added to substance C, then gas D was evolved and when dilute hydrochloric acid was added to part B then gas E was evolved.
- What type of substance is B ?
- What type of substance is C ?
- Name the gas (i) D, and (ii) E ?
- State one characteristic property of gas D.
- Write one test to identify gas E.
There are three substances X, Y and Z. The substance X does not have a fixed melting point or boiling point and it still shows the individual properties of its constituents. The substance Y is a pure substance which occurs in nature as such. The substance Y has a fixed melting point and boiling point but it cannot be broken down into simpler substances by any chemical means. The substance Z is also a pure substance whose properties are entirely different from those of its constituents. The substance Z can, however, be divided by electrolysis into two substances which belong to the same class of substances as Y.
- What type of substance could X be ? Name one substance like X.
- What type of substance could Y be ? Name one substance like Y.
- What type of substance could Z be ? Name one substance like Z.
- Which process involves absorption or release of an appreciable amount of energy : formation of substance X or formation of substance Z ?
- Name the three groups into which all the substances like Y are divided on the basis of their properties.
What is meant by the concentration of a solution ?
One of the following is a solid foam. This one is :
How will you separate a mixture containing sand and sugar ?
Celsius scale is a scale of temperature in which zero represents the melting point of ice and 100 represents the boiling point of water.
Evaporation is always accompanied by ______ in temperature.
