Answer:
c) There are sharp emission lines demonstrating discrete energy levels.
Explanation:
When an element emits energy in the form of radiation, it produces a spectrum of colors on a photographic plate. This spectrum can either be continuous or discrete. In continuous spectrum the spectrum continues without any discrimination between two regions. This represents the continuous emission of radiation, and thus the continuous emission of energy without any break.
On the other hand, the line spectrum consists of discrete and sharp lines, which shows the emission of radiation in a certain amount in a certain time, with a break between emission. Hence, the line spectra supports the quantization of energy.
The correct option is:
<u>c) There are sharp emission lines demonstrating discrete energy levels.</u>
Answer:
Mole Fraction of O2 --> 0.42
Mole Fraction of Ar --> 0.037
Explanation:
1. <em>Describe</em>
Frequency (f) and wavelength (λ) are inversely related.
f ∝ 1/λ
As one goes up, the other goes down and vice versa.
2. <em>Infer
</em>
The frequency of infrared light is less than that of red light, so infra could mean something like less than or below or beneath.
Ultrahigh frequencies are extremely high compared with those of visible light. Ultrasound has frequencies that are far beyond what we can hear. An ultracentrifuge goes at extremely high speed, and an ultramicroscope can “see” tiny structures. Ultra could probably mean something like extremely or far beyond.
3. <em>Analyze
</em>
Energy is directly proportional to frequency (E ∝ f).
Frequency is inversely proportional to wavelength (f ∝ 1/λ).
Energy is inversely proportional to wavelength (E ∝ 1/λ).
Answer:
Br- Withdraws electrons inductively
Donates electrons by resonance
CH2CH3 - Donates electrons by hyperconjugation
NHCH3- Withdraws electrons inductively
Donates electrons by resonance
OCH3 - Withdraws electrons inductively
Donates electrons by resonance
+N(CH3)3 - Withdraws electrons inductively
Explanation:
A chemical moiety may withdraw or donate electrons by resonance or inductive effect.
Halogens are electronegative elements hence they withdraw electrons by inductive effect. However, they also contain lone pairs so the can donate electrons by resonance.
Alkyl groups donate electrons by hyperconjugation involving hydrogen atoms.
-NHCH3 and contain species that have lone pair of electrons which can be donated by resonance. Also, the nitrogen and oxygen atoms are very electron withdrawing making the carbon atom to have a -I inductive effect.
+N(CH3)3 have no lone pair and is strongly electron withdrawing by inductive effects.
