Pure substances can or can not be chemically combined.
Pure substances can be either elements or compounds, but not mixture. Mixture are different substances mixing together without being chemically combined, such as air, which is a mixture of oxygen, carbon dioxide, water etc. Mixture can be separated by physical methods, like filtration or decantation.
Meanwhile, elements are the substances that cannot be further separated by any means. No matter physical or chemical methods. Examples of elements are oxygen, hydrogen, neon and all the other ones from the periodic table. Compounds are basically elements joining together, but they’re chemically combined which means their electrons (kind of subatomic particle) are either shared or given away. These elements can only be separated by chemical methods like electrolysis or heating.
Therefore, as long as the substance cannot be separated by physical methods, it can be considered as a pure substance. We can now conclude that pure substance can be (element) or can not be (compound) chemically combined.
The least dense layer of the earth is the crust.
Answer:
so the number of molecules in 8 moles of water is 4.8176×10^24
Explanation:
number of moles=8moles
avogadro's number=6.022×10²³
number of molecules=?
as we know that
substituting the equation
number of moles × avogdro's number=number of molecules
number of molecules=8moles×6.022×10²³
number of molecules=4.8176×10^24
i hope this will help you :)
Answer:
C6H12O6 + 6O2 → 6CO2 + 6H2O.
Explanation:
Q = M * C *ΔT
Q / <span>ΔT = M
</span>Δf - Δi = 98.4ºC - 62.2ºC = 36.2ºC
<span>
C = 1137 J / 140 * 36.2
C = 1137 / 5068
C = 0.224 J/gºC</span>
