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प्रश्न
State the property of the following substance.
Manganese dioxide, a catalyst which alters the rate of a chemical reaction is black in colour.
विकल्प
Physical
Chemical
उत्तर
Chemical
संबंधित प्रश्न
Give one difference between atoms and molecules.
Fill in the blanks:
Any matter which has a definite ______ but no definite shape is called a ______.
Describe simple experiments to prove that gases occupy space.
State the property of the following substance.
The melting point of ice is 0°C.
In solids, the space between the particles is less than in ______.
Solids are compressible.
The force of attraction between liquid particles is more than solid particles.
______ particles are tightly packed into a definite shape.
A strong current of trivalent gaseous boron passed through a silicon crystal decreases the density of the crystal due to part replacement of silicon by boron and due to interstitial vacancies created by missing Si atoms. In one such experiment, one gram of silicon is taken and the boron atoms are found to be 1000 ppm by weight, when the density of the Si crystal decreases by 12%. The percentage of missing vacancies due to silicon, which are filled up by boron atoms will be ____ g. [Given · Atomic wt. Si= 30, B = 11]
The composition of a sample of wustite is Fe0.93O1.0· The iron is present in the form of Fe(III) is ______%.
