Question
Explain why, diamond is hard while graphite is soft (though both are made of carbon atoms).
✓
Answer
A diamond crystal is a giant molecule of carbon atoms. Each carbon atom in the diamond crystal is linked to four other carbon atoms by strong covalent bonds. The four surrounding atoms are at the four vertices of a regular tetrahedron. This rigid structure of diamond makes it a very hard substance.
The structure of graphite is very different from that of diamond. A graphite crystal consists of layers of carbon atoms or sheets of carbon atoms and these layers are held together by weakVan der Waals forces. Due to this sheet like structure, graphite is a comparatively soft substance.
The structure of graphite is very different from that of diamond. A graphite crystal consists of layers of carbon atoms or sheets of carbon atoms and these layers are held together by weakVan der Waals forces. Due to this sheet like structure, graphite is a comparatively soft substance.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Draw a neat and labelled diagram to show the path of a ray of light in air and glass when the ray is incident obliquely on a glass slab. Show the (i) incident ray (ii) refracted ray (iii) emergent ray (iv) angle of incidence (v) angle of refraction (vi) angle of emergence in the diagram.
(OR)
Draw a neat and labelled diagram to show refraction of light through a glass slab.
(OR)
Draw a neat and labelled diagram to show refraction of light through a glass slab.
While diluting an acid, why is it recommended that the acid should be added to water and not water to the acid?
State the right hand thumb rule.
The calorific value and ignition temperature of fuel A are $55 \mathrm{~kJ} / \mathrm{g}$ and $80^{\circ} \mathrm{C}$, respectively. These values for fuel B are $80 \mathrm{~kJ} / \mathrm{g}$ and $10^{\circ} \mathrm{C}$, respectively. On burning, the fuel A produces $\mathrm{CO}_2$ and $\mathrm{H}_2 \mathrm{O}$ while the fuel B produces $\mathrm{CO}_2, \mathrm{CO}$ and $\mathrm{SO}_2$. Give three points of relative and disadvantages of these two fuels.
→Explain the term minimum distance of distinct vision.
(OR) Write a short note on distance of distinct vision.
(OR) Write a short note on distance of distinct vision.
What is meant by acquired and inherited traits? Explain with one example each.
Given below is a diagram showing a defect of vision. Name the defect of vision and draw an accurately labelled diagram to correct this defect.
A potential difference of 250 volts is applied across a resistance of 1000 Ω in an electric iron. Find (1) the current (2) the heat produced in joule in 12 seconds.
Keeping other conditions the same, if the length of the wire in the iron is reduced to half the original length (by cutting the wire), what will be the current and heat produced?
Keeping other conditions the same, if the length of the wire in the iron is reduced to half the original length (by cutting the wire), what will be the current and heat produced?
Two tungsten bulbs of wattage $100 \ W$ and $60 \ W$ power work on $220 \ V$ potential difference. If they are connected in parallel, how much current will flow in the main conductor?
→A man holds a spherical shaving mirror of radius of curvature 60cm, and focal length 30cm, at a distance of 15cm, from his nose. Find the position of image, and calculate the magnification.