<span>Answer:
For Lewis theory, the most stable species will have a complete octet for as many atoms as possible. Construct Lewis dot structures for each species. You should see that CN+ cannot give a complete octet to the C atom unless a quadruple bond - unknown except in transition metals - is formed. CN will have an odd number of electrons, and is thus a free radical and unstable with respect to dimerization (it forms cyanogen). CN-, the familiar cyanide ion, gives both C and N a complete octet with a triple bond, and is thus the most stable.
Molecular orbital theory is a bit more complex. Nitrogen and carbon are close enough in electronegativity, so the orbitals from the C atom will mix with the same orbitals from the N atom. The molecular orbitals formed will be sigma2s, sigma*2s, pi2p, sigma2p, pi*2p, and sigma*2p. The * denotes an antibonding orbital; these are higher in energy, and electrons placed into these orbitals weaken the bonding between two atoms. CN+ will completely fill the sigma2s, sigma*2s, and pi2p orbitals. CN will add an electron in the bonding sigma2p orbital, and the atoms are thus more strongly bonded than in CN+. CN- fills the sigma2p orbital, and the addition of another bonding electron means that this species has the strongest bond of the three. I might have the names of some of the filled levels incorrect; the energy levels of the sigma2p and pi2p swap at some point. This concept is hard to explain without a picture; see the link.
Thus, both MO and Lewis theory predict CN- as the most stable species, a prediction that matches well with experimental data.</span>
Answer:

Explanation:
Let consider that the person hit the ground in the negative direction. The physical model for the impact is modelled after the Impact Theorem:

The impact is:



The force of impact is derived as follows:



8 m/s
Explanation:
Using conservation of momentum :-

Where:
m1 = Mass of first vehicle
m2 = Mass of second vehicle
u1 = initial speed of first vehicle
v1 = initial speed of second vehicle
u2 = Final speed of first vehicle
v1 = Final speed of second vehicle
From the received informations:



So

Now divide both sides by m1 :-


Therefore, final answer is 8 m/s
Answer:
The wavelength is 2 meters
Explanation:
The relationship between the frequency, the speed and the wavelength is given by the relation;
v = f × λ
The given parameters are;
The distance of the duck from the edge of the pond = 12 m
The number of ripples produced per second = Frequency, f = 2 Hz
The time it takes the ripple to reach the edge of the pond after travelling past the duck = 3 seconds
Therefore, speed of the wave, v = Distance/time = 12 m/(3 s) = 4 m/s
The wavelength, λ, is therefore;
λ = v/f = (4 m/s)/(2 Hz) = 2 meters.
Scientists could investigate this idea by making cathode ray tubes out of different materials to see if the ray was the same.