Answer: E
=
1.55
⋅
10
−
19
J
Explanation:
The energy transition will be equal to 1.55
⋅
10
−
1
J
.
So, you know your energy levels to be n = 5 and n = 3. Rydberg's equation will allow you calculate the wavelength of the photon emitted by the electron during this transition
1
λ =
R
⋅
(
1
n
2
final −
1
n
2
initial )
, where
λ
- the wavelength of the emitted photon;
R
- Rydberg's constant - 1.0974
⋅
10
7
m
−
1
;
n
final
- the final energy level - in your case equal to 3;
n
initial
- the initial energy level - in your case equal to 5.
So, you've got all you need to solve for λ
, so
1
λ =
1.0974
⋅10 7
m
−
1
⋅
(....
−152
)
1
λ
=
0.07804
⋅
10
7
m
−
1
⇒
λ
=
1.28
⋅
10
−
6
m
Since
E
=
h
c
λ
, to calculate for the energy of this transition you'll have to multiply Rydberg's equation by
h
⋅
c
, where
h
- Planck's constant -
6.626
⋅
10
−
34
J
⋅
s
c
- the speed of light -
299,792,458 m/s
So, the transition energy for your particular transition (which is part of the Paschen Series) is
E
=
6.626
⋅
10
−
34
J
⋅
s
⋅
299,792,458
m/s
1.28
⋅
10
−
6
m
E
=
1.55
⋅
10
−
19
J
the answer is A.) the moon is orbiting the earth once per month
its the only logical answer, the others are either impossible or illogical
Answer:
Alpha particle or helium nuclei.
Explanation:
Alpha particle:
Alpha particle is emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number less than 2 as compared to parent atom the starting atom.
Properties of alpha radiation:
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴ + energy
Answer: HCl+NaHCO₃=NaCl+CO₂+H₂O
Explanation:
Answer:
5.25g
Explanation:
We'll begin by writing the balanced equation for the reaction. This is shown below:
Na2SiO3 + 8HF → H2SiF6 + 2NaF + 3H2O
From the balanced equation above,
8 moles of HF reacted to produce 2 moles of NaF.
Therefore, 0.5 moles of HF will react to produce = (0.5 x 2)/8 = 0.125 mole of NaF.
Next, we shall convert 0.125 mole of NaF to grams.
This is illustrated below:
Mole of NaF = 0.125 mole
Molar mass of NaF = 23 + 19 = 42g/mol
Mass of NaF =..?
Mass = mole x molar mass
Mass of NaF = 0.125 x 42
Mass of NaF = 5.25g
Therefore, 5.25g of NaF is produced from the reaction.
