First we find for the wavelength of the photon released due
to change in energy level. We use the Rydberg equation:
1/ʎ = R [1/n1^2 – 1/n2^2]
where,
ʎ is the wavelength
R is the rydbergs constant = 1.097×10^7 m^-1
n1 is the 1st energy level = 1
n2 is the higher energy level = infinity, so 1/n2 = 0
Calculating for ʎ:
1/ʎ = 1.097×10^7 m^-1 * [1/1^2 – 0]
ʎ = 9.1158 x 10^-8 m
Then calculate the energy using Plancks equation:
E = hc/ʎ
where,
h is plancks constant = 6.626×10^−34 J s
c is speed of light = 3x10^8 m/s
E = (6.626×10^−34 J s * 3x10^8 m/s) / 9.1158 x 10^-8 m
E = 2.18 x 10^-18 J = 2.18 x 10^-21 kJ
This is still per atom, so multiply by Avogadros number =
6.022 x 10^23 atoms / mol:
E = (2.18 x 10^-21 kJ / atom) * (6.022 x 10^23 atoms /
mol)
E = 1312 kJ/mol
Answer:
Ionic substance
Explanation:
An ionic substance is formed when oppositely charged ions link up to form an infinitely large lattice structure that can only be described in terms of unit cells.
Ionic substances may consist of billions of oppositely charged ions. Ionic substances are hard, have high melting and boiling points and do not conduct electricity in the solid state because the ions are not free in the solid state.
However, in solution or molten state, the substance conducts electricity since the ions which are the charge carriers are now mobile.
Answer:
Option C.
2 Mg (s) + O₂(g) → 2MgO (s)
Explanation:
Two moles of magnesium solid react with one mol of oxygen gas to
form two moles of magnesium-oxide solid
2 Mg (s) + O₂(g) → 2MgO (s)
That's the reaction for the magnessium oxide's formation.
Be careful cause we do not say molecules, they are moles.
The stoichiometry indicates the number of moles that react and the moles which are produced.
It is a redox reaction, because the magnessium is oxidized and the oxygen is reduced. Both elements, changed the oxidation states.
