1. A radical is a reactive intermediate with a single ____________ electron, formed by ____________ of a covalent bond.
1. A: Unpaired, and homolysis
2. Allylic radicals are stabilized by ____________ , making them ____________ stable than tertiary radicals.
2. A: Resonance, and more
3. A compound that contains an especially weak bond that serves as a source of radicals is called a radical ____________ .
3. A: Initiator
4. Treatment of cyclohexene with N-bromosuccinimide in the presence of light leads to ____________ by ____________ intermediates.
4. A: Allylic substitution by radical
Answer: The energy of an electron in the n = 2 level of a hydrogen atom is 3.40 eV.
Explanation:
Given: n = 2
The relation between energy and
orbit of an atom is as follows.

Substitute the values into above formula as follows.

The negative sign indicates that energy is being released.
Thus, we can conclude that the energy of an electron in the n = 2 level of a hydrogen atom is 3.40 eV.
The answer would be 5. because the last zero is a holding place because the number is in front of the decimal. They other zero counts because they are being sandwiched.<span />
Answer:
1. Hubble
2.Aristarchus
3.Galileo
4.Aristotle
5.Kepler
6.Jupiter
7.Mercury
8.Uranus
9.Venus
10.Earth
11. Jupiter and Mars
12. sun
13.D
14. Saturn
15.Gas giants
16.Kuiper Belt and Ceres,Pluto,eris and haumea.
17.pluto
18.Ptolemy's model
19.meteor- a small body of matter from the outer surface that enters the earth's atmosphere.
meteoroid- a small body moving in the solar system that would become a meteor if it enters the earth's atmosphere.
meteorite- a piece of rock or metal that has fallen to the earth's surface from outer space as a meteor.
the relationship is the diagram I drew at the top.
hope this was helpful
The answer to the question is Dna