Because Na⁺ ion lacks an electron and O²⁻ has two extra electrons extra, to balance the charge, we need 2 Na⁺ ions.
All ions, atoms and molecules want to get to the minimum energy state, and that state is when the ion, atom, or molecule is neutral, that's why all of them want to balance their charges.
The displacement of a moving object is the straight-line distance between the place it starts from and the place where it stops.
The displacement of anything moving along a circular track depends on how far around it goes before it stops. The greatest displacement it can possibly have is the diameter of the track ... 100m on this particular one ... because that's as far apart as two places on a circle can ever be.
The most interesting case is when the object goes around the circle exactly once. Then it stops at the same place it started from, the distance between the starting point and ending point is zero, and after all that motion, the displacement is zero.
Answer:
Because they are beneficial
Explanation:
There are microorganisms in our large intestine that synthesis vitamins and allow them to be absorbed into the bloodstream. However a tiny minority are pathogens (disease-causing agents). These pathogens often called germs or bugs, are a threat to all life forms.
Answer:
The acceleration of Abbie is half of the Zak's.
Explanation:
The centripetal acceleration of an object on a circular path is given by :

Two children are riding on a merry-go-round that is rotating with a constant angular speed. Let
is distance of Abbie from the merry-go-round and
is distance of Zak's from the merry-go-round. Acceleration of Abbie is :
...... (1)

Acceleration of Zak's is :
.......(2)

Dividing equation (1) and (2) we get :

So, the acceleration of Abbie is half of the Zak's.