answer is A
The kinetic theory is used to explain the behaviour of gases.
One of the assumptions states that "a gas is composed of a large number of identical molecules moving at different speeds".
Explanation:
Sodium metal reacts rapidly with water to form a colourless basic solution of sodium hydroxide (NaOH) and hydrogen gas (H2). The reaction continues even when the solution becomes basic. The resulting solution is basic because of the dissolved hydroxide.
Answer:
Newton's First Law states that an object in motion will stay in motion, an object at rest will stay at rest, at a constant velocity, unless an unbalanced force acts upon it.
Newtons First law of motion has to do with seat belts because think about it, what happens when we don't wear a seat belt and our vehicle comes to a quick stop. What happens to you? You move forward and stay in motion until an unbalanced force acts upon you. Now what is an unbalanced force? An unbalanced force is one that is not opposed by an equal and opposite force operating directly against the force intended to cause a change in the object's state of motion or rest. So, when you come to a stop, you wouldn't stop motion unless a force is caused to change your motion and put you at rest. If you were wearing a seat belt, the seat belt would act as the unbalanced force, it would stop you from being in motion.
Answer: an increase in the concentration of
in aqueous solutions and is capable of donating one or more 
Explanation:
According to Arrhenius concept, a base is defined as a substance which donates hydroxide ions
when dissolved in water and an acid is defined as a substance which donates hydrogen ions
in water.
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.
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.
Thus According to the Arrhenius concept, an acid is a substance that causes an increase in the concentration of
in aqueous solutions and is capable of donating one or more 
Balanced equation = 2 NaHCO3 —-> Na2CO3 + H2O + CO2
Can you mark me as brainliest?