Change the bond between the two carbon atoms in each molecule to a double or triple bond as needed to complete the structure. If the bond should remain a single bond, then you do not need to do anything to the bond. Do not change any other bonds in the molecules.

The first should be left asis because carbon already has 4 bonds/8 electrons

The second needs to have a double bond to give carbon 4 bonds/8 electrons

The third must have a triple bong between the carbons to give them both 4 bonds/8 electrons

Explanation:

Make sure Hydrogen only has 1 bond/2 electrons at all times. Carbon needs a total of 4 bonds/8 electrons

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied