Answer:
The wavelength of the radio wave is 3.003 m.
The energy of the radio wave is
.
Explanation:
Frequency of the radio waves, ν = 99.9 MHz = 
Wavelength and frequency are related to each other by realtion:

= Wavelength of the wave
c = speed of the light
ν = Frequency of the wave

The wavelength of the radio wave is 3.003 m.
The energy of the electromagnetic wave is given by Planck's equation:

h = Planck's constant = 
The energy of the radio wave with 99.9 MHz frequency will be:


The energy of the radio wave is
.
38 g / (3 x 10^23 molecules) * 6,02x10^23 molecules/mol = 76,25 g/mol.
Answer:
1.48×10²⁴ Cu atoms
Explanation:
For this question you need to use Avogadro's number 6.022×10²³atoms.
2.45 moles of Cu ×
= 1.47539×10²⁴ atoms.
The moles cancel out so you are left with atoms.
Since there are 3 significant figures in the question there should be 3 significant figures in your answer, which is 1.48×10²⁴ Cu atoms.
Answer:
<h2>
The bombing of Hiroshima ended World War II.</h2>
Explanation:
[The scientific method includes these steps:
Observation
Hypothesis
Experimentation
Data Analysis
Conclusion]
The first two Hypothesis can be tested with the scientific method, you cannot go back in time and observe or experiment with the bombing of Hiroshima to deduce whether or not it ended World War II.
The answers are a.) 0.03 mol KOH requires 0.03 mol HCl, b.) 2 mol NH3 requires 2 mol HCl and c.) 0.1 mol Ca(OH)2 requires 0.2 mol HCl.
Solution:
We need to write the balanced equations for each reactions to find out the stoichiometry for each reactants.
a.) HCl (aq) + KOH (aq) → KCl (aq) + H2O(ℓ)
From the balanced equations, we can see that 1 HCl reacts with 1 KOH, therefore if 0.03 mol KOH is reacted then 0.03 mol HCl must also be present.
b.) HCl(aq) + NH3(aq) ) → NH4Cl(aq)
If 2 moles of NH3 are reacted then 2 moles of HCl must also be present since 1 HCl reacts with 1 NH3 from the balanced reaction.
c.) 2HCl(aq) + Ca(OH)2(s) → CaCl2(aq) + 2H2O(ℓ)
We can see that 2 HCl react with 1 Ca(OH)2, hence if 0.1 mol of Ca(OH)2 is reacted then 0.2 mol HCl must also be present.