Answer:
Coal is a traditionally used source of energy, there are main four types of ranks for coal. Here the rank of a coal means to a natural process called Coalification, which takes place during a plant is buried and changes to a harder, and denser material and become even more rich in carbon contents.
Anthracite is know to have the highest ranked coal, it contains highest percent of fixed carbon and lowest percent of volatile material.
Radon is produced by uranium rocks underneath a house.
Answer:
160 gm
Explanation:
Five times as much water means you can dissolve 5 times as much potassium nitrate 5 x 32 = 160 gm <u> <===== this seems unlikely though as I doubt 32 g of potassium nitrate will dissolve in only 1 cm^3 of water 1 cm^3 of water is only 1 gm of water </u>
A, B, and C are insoluble in water
Answer: Chemical change
Explanation:
Physical change is a change in which there is no rearrangement of atoms and thus no new substance is formed. There is only change in physical state of the substance. The change can be reversed using physical methods.
Chemical change is a change in which there is rearrangement of atoms and thus new substance is formed. There may or may not be a change in physical state. The change can only be reversed using chemical methods.
Thus when iron and sulfur are heated in a test tube, the chemical change occurs and thus lead to formation of new substances which could not be separated using magnet.
