Which statement is true about sodium chloride (NaCl)?

It is a salt because it decreases the concentration of metallic ions.
It is an acid because it is formed by the reaction of a salt and an acid.
It is a salt because it is formed by the reaction of an acid and a base.
It is an acid because it increases the concentration of nonmetallic ions

The correct answer is : It is a salt because it is formed by the reaction of an acid and a base.

Explanation:

Sodium chloride is formed from the neutralization reaction between a strong acid (hydrochloric acid) and a strong base (sodium hydroxide):

HCl + NaOH ---> NaCl + H20

By reacting strong acid and base, they neutralize each other resulting in a salt (NaCl) and water.

Corresponds to an exothermic reaction (heat is released).

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j

put the answers   and i could answer.