Mendeleev’s was organized in atomic mass whereas the modern periodic table is organized by atomic number
Answer is: volume of helium is 244.72 liters.
m(He) = 43.7 g.
n(He) = m(He) ÷ M(He).
n(He) = 43.7 g ÷ 4 g/mol.
n(He) = 10.925 mol.
V(He) = n(He) · n(He).
V(He) = 10.925 mol · 22.4 L/mol.
V(He) = 244.72 L.
Vm - molar volume at STP.
n - amount of substance.
Because of the plates crashing into each other
Basically, this figure represents scattering of alpha particles by the atoms of a gold foil.
- Here, A represents that a few alpha particles are deflected through large angle. It shows that the nucleus of the atom is positively charged which repels the positively charged alpha particles and deflect them from their original path.
- B represents that most alpha particles pass straight through the gold foil without any deflection from their original path. The reason is that there is a lot of empty space in the atom.
- C represents that some alpha particles are deflected through small angles. The reason is same as that of A.
Hope you could understand.
If you have any query, feel free to ask.
Answer:
D. An endangered species is in danger of becoming extinct in the near future. A threatened species could become endangered in the near future.
Explanation: