In a collision between an electron and a hydrogen atom, it is useful to select both objects as the system because which of these:

1
the total momentum of the system does not change during the collision.

during the time interval just before to just after the collision, external forces are negligible.

the kinetic energy of a two-object system is nearly zero.

the sum of the final kinetic energies must equal the sum of the initial kinetic energies for a two-object system.

the forces the objects exert on each other are internal to the system and don't change the total momentum of the system

Explanation:

Because of the following ,it is useful to select both objects as the system during  collision between an electron and a hydrogen atom

1. The total momentum of the system does not change during the collision.

2.The forces the objects exert on each other are internal to the system and don't change the total momentum of the system.

3. During the time interval just before to just after the collision, external forces are negligible.

d) physical means can be used to separate the components of air.

the journeys of marquette, joliet and la salle a) new france expand.

all three of these explorers explored the midwest and the area around the great lakes, which they subsequently claimed for france.

this was a big portion of territory and expanded new france which before then only consisted of quebec province in northeastern canada