Answer:
The hydrogen atom has just one electron, but many spectral lines. However it contains many shells and the movement of that electron from one shell to another causes the release of energy and also an emission of photons.
A spectral line are dark or bright lines formed within a specific frequency range which differ from other frequencies.Because of the difference of energy for the various shells, it produces different wavelengths and this is the reason for the many spectral line for hydrogen.
Chemical reaction: Ba(NO₃)₂ + H₂SO₄ → BaSO₄ + 2HNO₃.
V(H₂SO₄) = 250 mL ÷ 1000 mL/L = 0,25 L.
m(BaSO₄) = 0,55 g.
n(BaSO₄) = m(BaSO₄) ÷ M(BaSO₄).
n(BaSO₄) = 0,55 g ÷ 233,38 g/mol.
n(BaSO₄) = 0,00235 mol.
From chemical reaction: n(BaSO₄) : n(Ba(NO₃)₂) = 1 : 1.
n(Ba(NO₃)₂) = 0,00235 mol.
c(Ba(NO₃)₂) = n(Ba(NO₃)₂) ÷ V.
c(Ba(NO₃)₂) = 0,00235 mol ÷ 0,25 L.
c(Ba(NO₃)₂) = 0,0095 mol/L.
28) All elements are made of atoms
29)Protons and Neutrons
-Electrons make up the outside of the Nucleus
