Answer:
The frequency of the electromagnetic wave is 7.22891566 × 10¹⁴ Hz
Explanation:
The wavelength of the electromagnetic wave, λ = 415 nm
The speed of an electromagnetic wave, c ≈ 3.0 × 10⁸ m/s
Given that an electromagnetic wave is a periodic wave, we have;
The speed of the electromagnetic wave, c = f×λ
Where;
f = The frequency of the electromagnetic wave
Therefore, we have;
f = c/λ
From which we have;
f = (3.0 × 10⁸ m/s)/(415 nm) = 7.22891566 × 10¹⁴ /s = 7.22891566 × 10¹⁴ Hz
The frequency of the electromagnetic wave, f = 7.22891566 × 10¹⁴ Hz
The combustion of 1 mole of methane (CH4) in a domestic furnace requires 2 moles of O2 molecules, assuming the combustion was complete or ideal. To solve this problem, use stoichiometry of the reaction's balanced chemical equation:
CH4 + 2O2 --> CO2 + 2H2O
The ratio of CH4 to O2 in terms of moles is 1:2. So 1 mole of CH4 needs 2 moles of O2.
Answer:
The last option:
- NH₃ (aq) + H⁺ (aq) → NH₄⁺ (aq)
Explanation:
1) Word equation
- Aqueous ammonia + nitric acid → aqueous ammonium nitrate
2) Chemical (molecular) equation
- NH₃ (aq) + HNO₃ (aq) → NH₄ NO₃
3) Ionization reactions
Write the dissociation of the soluble ionic compounds:
4) Total ionic equation:
- NH₃ (aq) + H⁺ (aq) + NO₃⁻ (aq) → NH₄⁺ (aq) + NO₃⁻ (aq)
5) Net ionic equation
You must cancel the spectator ions, which are those ions that are repeated in both reactant and product sides, i.e. NO₃⁻. They are name spectator because they do not participate (change) during the reaction.
- NH₃ (aq) + H⁺ (aq) → NH₄⁺ (aq)
And that is the last choice of the list.
Answer:
Acid Phosphatase (AP) Test
Explanation:
Acid phosphate is an enzyme that is found in the body. It is secreted majorly by the prostrate gland into the seminal fluid. The acid phosphatase test is used to test for the presence of semen in items.
Scott chose the acid phosphatase test because it is very useful in testing for semen on large items such as blankets. The reaction time for an acid phosphatase test for semen is less than 30 seconds. Seeing that the test was completed in three minutes, Scott concluded that the positive reaction was as a result of some other fluid.
The detectives reported that an overturned bowl of grapes and watermelon was found at the scene as well as a broken glass that had contained wine. Scott knew that some fruit juices like that of watermelon give a positive reaction to the acid phosphatase test but with more time that of the semen fluid because the reaction is a very slow one.
Scott concluded that there was no presence of semen on the blanket and therefore there was no sexual assault.