Substances that have a define size and shape and vibrating particles that are close together are called Solid.
Explanation:
There are three states of matter - solid, liquid and gas.
Lets talk about solid state in detail.
In solid particles are closely packed and so they have very less or no space to move which results in vibrating particles. This results in solid substances having a fixed shape and volume.
The particles have very little space in between them, so it is not easy to compress solid.
There is no free space for particles to slide over each other, which does not allow solids to flow.
Also, particles in solid have a regular arrangement, they are not randomly packed.
Fe2O3 + 2Al ---> Al2O3 + 2Fe
Mole ratio Fe2O3 : Al = 1:2
No. of moles of Fe2O3 = Mass/RMM = 250 / (55.8 * 2 + 16 * 3) = 1.56641604 moles
No. of moles of Al = 150/27 = 5.555555555 moles.
Mole ratio 1 : 2. 1.56641604 * 2 = 3.13283208 moles of Al, but you have 5.555555555 moles of Al. So Al is in excess. All of it won't react.
So take the Fe2O3 and Fe ratio to calculate the mass of iron metal that can be prepared.
RMM of Fe2O3 / Mass of Fe2O3 = RMM of 2Fe / Mass of Fe 159.6 / 250 = 111.6 / x x = 174.8 g of Fe
B. Earth’s tilt
Earth’s tilt exposes different parts of the earth to varying degrees of sunlight throughout the year, causing seasons.
Answer:
344 nm is the longest wavelength of radiation with enough energy to break carbon-carbon bonds.
Explanation:
,ΔH = 348 kJ/mol
Energy required to break 1 mole of C-C bond = 348 kJ
Energy required to break 1 C-C bond = E

Energy related with the wavelength of light is given by Planck's equation:





344 nm is the longest wavelength of radiation with enough energy to break carbon-carbon bonds.
The answer is true due to the saponification of the fatty substances on the surface of the skin.