<span>The key difference between Mendeleev and modern periodic table is that Mendeleev’s periodic table was based on the increasing atomic masses while the modern periodic table is based on the increasing atomic numbers. Let us see here what is Mendeleev periodic table and what is modern periodic table, and then compare both to understand the difference between both periodic tables. Mendeleev is the pioneer of the modern periodic table, though a numerous number of changes had been made to the old version of the periodic table. Both of these attempts are equally important to the scientific community; because without an invention of the periodic relationship in elements, the modern developments in Science would not reach a development era as today. Before the invention of Mendeleev’s classification, there were several attempts made by several chemists, but their periodic laws were inadequate to apply for all the elements. The modern periodic table is so advantageous for the development in the Science.</span>
Which soil horizon is mostly composed of organic matter?
It is only between 5 to 10 inches thick and consists of organic matter and minerals. This is the soil layer where plants and organisms primarily live. B: This layer is also called Subsoil. It is mostly made of clay, iron minerals as well as organic matter, which has been washed down to this horizon by rainwater.
The option that is not a basic method used by ecologists to study the living world is B. animal training, whereas they do experimenting, modeling, and observing as part of their study of the living world.
There are animal trainers whose job it is to train animals - ecologists don't have to do that.
<h3>The density of H₂ = 0.033 g/L</h3><h3>Further explanation</h3>
In general, the gas equation can be written
![\large {\boxed {\bold {PV = nRT}}}](https://tex.z-dn.net/?f=%5Clarge%20%7B%5Cboxed%20%7B%5Cbold%20%7BPV%20%3D%20nRT%7D%7D%7D)
where
P = pressure, atm , N/m²
V = volume, liter
n = number of moles
R = gas constant = 0.082 l.atm / mol K (P= atm, v= liter),or 8,314 J/mol K (P=Pa or N/m², v= m³)
T = temperature, Kelvin
n = N / No
n = mole
No = Avogadro number (6.02.10²³)
n = m / MW
m = mass
MW = molecular weight
For density , can be formulated :
![\tt \rho=\dfrac{P\times MW}{R\times T}](https://tex.z-dn.net/?f=%5Ctt%20%5Crho%3D%5Cdfrac%7BP%5Ctimes%20MW%7D%7BR%5Ctimes%20T%7D)
P = 327 mmHg = 0,430263 atm
R = 0.082 L.atm / mol K
T = 48 ºC = 321.15 K
MW of H₂ = 2.015 g/mol
The density :
![\rho=\dfrac{0,430263\times 2.015 }{0.082\times 321.15}\\\\\rho=0.033~g/L](https://tex.z-dn.net/?f=%5Crho%3D%5Cdfrac%7B0%2C430263%5Ctimes%202.015%20%7D%7B0.082%5Ctimes%20321.15%7D%5C%5C%5C%5C%5Crho%3D0.033~g%2FL)
Answer: The given statement is true.
Explanation:
It is known that due to increase in temperature ice melts. Therefore, during ice age there is also melting of ice and solid state of water changes into liquid state of water.
Therefore, this water moves from its initial place and changes its position result in the change of land and specific areas.
Thus, we can conclude that the statement during an ice age, land can move and specific areas can be permanently changed is true.