The neutral pH is 7. Less than 7 indicates an acid and more than 7 indicates a base (up to 14).
<span>
NaCl - it's a salt (we can't measure the pH)
H2O - it can be an acid but also a base (the pH it is almost neutral,meaning close to 7 )
HF - it is a strong acid
</span><span>
KOH
- it is a strong base (pH=14)
</span>
↓
He needs to use HF (Hydrogen fluoride) to decrease the pH.
Answer:
upwards
downwards
Explanation:
Given:
weight of the person, 
So, the mass of the person:



- Now if the apparent weight in the elevator,

<u>Then the difference between the two weights is :</u>


is the force that acts on the body which generates the acceleration.
Now the corresponding acceleration:


upwards, because the normal reaction that due to the weight of the body is increased here.
- Now if the apparent weight in the elevator,

<u>Then the difference between the two weights is :</u>


is the force that acts on the body which generates the acceleration.
Now the corresponding acceleration:


downwards, because the normal reaction that due to the weight of the body is decreased here.
Gravity if I’m not mistaken
We calculate the coordinates at t₁ = 9 min and t₂ = 10 min, since the 10th minute is between t₁ and t₂.
As it leaves from rest, it means that the initial speed is zero
t₁=9 min=540 s
t₂=10 min=600 s
x₁=at₁²/2=8*540²/2=4*291600=1166400 m
x₂=at₂²/2=8*600²/2=4*360000=1440000 m
Δx=x₂-x₁=1440000-1166400=273600 m represents the distance traveled by the car in the 10th minute of travel
<span>If a mouse and an elephant both run with the same kinetic energy, can you say ... 3. if a car traveling at60 km/h will skid 20 m when its brakes lock, how far will it skid if it is traveling at 120 km/h when its brakes lock? (This question is typical on ...</span><span>just get this and figure it out and this is your answer </span>