Question

1. Write the formula of lead sulphate
2. Mention the general formula of alkyne compounds
3. Which allotrope of carbon is very hard
4. How does the atomic radius change as u go from left to right on a periodic table
5. Write the valency of an element having atomic number 13
6. The type of image formed by eye lens is
7. ENT specialist uses ---- in small aperture
8. The SI unit of the electric power is
9. A fuel gas that is produced anaerobically from biomass is

Answer 1

Hydrocarbons that contain carbon-carbon single bonds are alkanes. Carbon –carbon double bonds containing alkenes and carbon-carbon triple bonds are called alkynes. Carbon has 3 allotrope diamonds, graphite, and buckminsterfullerene. Anaerobic means in the absence of oxygen.

Complete answer:
1. Write the formula of lead sulphate- charge on lead is+2 and charge on sulphate ion is +2
Chemical formula: $PbSO4$
2. Mention the general formula of alkyne compound- alkynes are unsaturated hydrocarbons having triple bonds between carbon and carbon. The general formula for alkynes will be ${C_n}{H_{2n - 2}}$
3. Which allotrope of carbon is very hard- some chemical elements exist in two more different forms, in different conditions, are known as allotropes of that element. The atoms of that element are bonded together in different forms. Therefore their physical property will be different. Carbon has three allotrope diamonds, graphite and buckminsterfullerene. Out of the three diamonds it is hard.
4. How does the atomic radius change as u go from left to right on a periodic table- atomic radius decreases on going from left to right in a periodic table, as the shell remains same but nucleus charge increases and hence the effective nuclear charge increases and attractive force between electron and nucleus increases and size decreases.
5. Write the valency of an element having atomic number 13
Electronic configuration: 2, 8, 3
When we distribute the electrons in the shell, the outermost M shell will have 3 electrons. Therefore the bonding capability of this atom is 3. Hence valency is 3.
6. The type of image formed by an eye lens is- eye forms an image on the retina with light rays coming from an object. The eye form real and inverted image of that object on retina
7. ENT specialist uses concave mirrors. The concave mirror converges all the light. And images formed by this mirror are larger in size than original.
8. The SI unit of electric power is watt (W)
9. A fuel gas that is produced anaerobically from biomass is- methane gas is produced from biomass

Note:
In all the allotropes of carbon, atoms are joined by covalent bonds but in different arrangements that the property of allotropes is very different. Allotropes have the same chemical properties. While diamond is hard, has a high melting point, reflects light, bad conductor of electricity, while graphite is soft, has a lower melting point than diamond, does not reflect light and is a good conductor of light .