Answer:
The correct answer is : 
Explanation:
According to the Bronsted Lowry conjugate acid-base theory, an acid is defined as a substance which donates protons and a base is defined as a substance which accepts protons.
Acid after donating protons changes into conjugate base and base after accepting protons changes into conjugate acid.
So, when HF in water reacts, it form fluoride ions and hydronium ions. The recation is given as:

Here, HF is acting as a Bronsted Lowry acid by donating proton and forms it conjugate base
, Where as water is acting as a Bronsted Lowry base by accepting a proton and forms its conjugate acid
.
Answer:
<h2>9 kg.m/s</h2>
Explanation:
The momentum of an object can be found by using the formula
momentum = mass × velocity
From the question we have
momentum = 3 × 3
We have the final answer as
<h3>9 kg.m/s</h3>
Hope this helps you
Answer:
When we stand on the floor, we apply a force on the floor surface in the downward direction and in return the floor also exerts an upward and equal force on us.
Explanation:
Newton' third law is vey famous and it states that for each and every action, there applies an equal but opposite reaction. Thus the action force and the reaction force always acts on pairs. But they does not contribute to the motion of the object.
One such example that illustrates the action and reaction force from Newton's law is when we stand on the floor we exert a force on the floor surface in downward direction. The floor surface also exerts an opposite and equal force on us in the upward direction.