B: Extension Lines! You could have just searched this up on google
Momentum = (mass) x (speed)
If the speed is zero, then the momentum is zero.
Answer:
The Doppler shift may be helpful to determine the relative speed of an object by bouncing a wave (usually a radar wave) off the object and measuring the shift in the frequency of the wave.
Explanation:
Doppler shift helps to overcome a visual illusion block out irrelevant noises, locate sounds and see an object in very dim light by determining the relative speed of an object by bouncing a wave
Elements with 7 valence electrons are extremely reactive, while elements with 8 valence electrons practically don't react at all.
This is caused by the fact that all molecules want to have 8 valence electrons; that's just the scientific fact. So, if an element already has 8 valence electrons, it doesn't need to react with anything. If the element only has 7 valence electrons, however, it really wants to react with something with 1 valence electron to get to that special number 8.