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.

8 0

3 years ago

What is the percent yield for a reaction if we predicted the formation

bogdanovich [222]

Answer:

18.1%

Explanation:

5 0

3 years ago

What is the percent composition of hydrogen in NH4HCO3?

Readme [11.4K]

To find the Percent Composition of an atom, you use this formula:
Mass of element in the compound you're studying on ( in this case it's 5 since there is 5 Hydrogens) over the mass of the compound (which is here 79), Multiplied by 100 since you want a percent.
So we get:
$\frac{5}{79} * 100$
So you get about:
$0.063 * 100$
$6.3$

So, the percent composition of Hydrogen in NH4HCO3 is 6.3%

Hope this Helps! :D

7 0

3 years ago

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