Answer:
Option B. 4.25×10¯¹⁹ J
Explanation:
From the question given above, the following data were obtained:
Frequency (f) = 6.42×10¹⁴ Hz
Energy (E) =?
Energy and frequency are related by the following equation:
Energy (E) = Planck's constant (h) × frequency (f)
E = hf
With the above formula, we can obtain the energy of the photon as follow:
Frequency (f) = 6.42×10¹⁴ Hz
Planck's constant (h) = 6.63×10¯³⁴ Js
Energy (E) =?
E = hf
E = 6.63×10¯³⁴ × 6.42×10¹⁴
E = 4.25×10¯¹⁹ J
Thus, the energy of the photon is 4.25×10¯¹⁹ J
Answer: nebula
Explanation: All stars start off in a large cloud of dust and gas which is called a nebula.
Answer:
The density of Lithium β is 0.5798 g/cm³
Explanation:
For a face centered cubic (FCC) structure, there are total number of 4 atoms in the unit cell.
we need to calculate the mass of these atoms because density is mass per unit volume.
Atomic mass of Lithium is 6.94 g/mol
Then we calculate the mass of four atoms;

⇒next, we estimate the volume of the unit cell in cubic centimeter
given the edge length or lattice constant a = 0.43nm
a = 0.43nm = 0.43 X 10⁻⁹ m = 0.43 X 10⁻⁹ X 10² cm = 4.3 X 10⁻⁸cm
Volume of the unit cell = a³ = (4.3 X 10⁻⁸cm)³ = 7.9507 X 10⁻²³ cm³
⇒Finally, we calculate the density of Lithium β
Density = mass/volume
Density = (4.6097 X 10⁻²³ g)/(7.9507 X 10⁻²³ cm³)
Density = 0.5798 g/cm³
Explanation:
where are the chemical reactions and their properties to match ?????????