PLeeease help im so tired and i need to SLEEP. Answer the 1s you know

1 answer:

3 0

1. when the ball is just starting to fall, it has high potential but low kinetic energy. when it hits the floor, it has high kinetic but low potential energy
2. heat energy
3. reflective-transparent would be best, as they can reflect some light while let other light through, reflective-opaque would be useless in any circumstances because no light at all would be able to get through

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Help please fast will mark as Brainliest

wlad13 [49]

Answer:

The answer is 2i on right hand side.

Explanation:

We should star by checking the equation from right.

First we check how many Zn r there in left hand side. Which is 1. Let us check how many Znr there in right hand side, there is 1.So Zn is balanced, and don't worry about Znplus2 on right hand side it is just the ions not how many zinc r there.

Now let us check how many I are there left hand side. Which is 2. Now how many I are there in right hand side? Only 1.

So we put 2 behind I.

Now there r 2 I on both sides.

Its simple actually.

3 0

3 years ago

Read 2 more answers

On the basis of the information above, a buffer with a pH = 9 can best be made by using

telo118 [61]

Answer:

D H2PO4– + HPO42–

Explanation:

The acid dissociation constant for $\mathbf{H_3PO_4 , H_2PO^{-}_4 , HPO_4^{2-}}$ are $\mathbf{7\times 10^{-3}, \ \ 8\times 10^{-8} ,\ \ 5\times 10^{-13}}$ respectively.

$\mathbf{pka (H_3PO_4) = -log (7\times 10^{-3} )=2.2}$

$\mathbf{pka (H_2PO_4^-) = -log (8\times 10^{-8} )=7.1}$

$\mathbf{pka (HPO_4^{2-}) = -log (5\times 10^{-13} )=12.3}$

The reason while option D is the best answer is that, the value of pKa for both

$\mathbf{H_2PO^{-}_4 ,\ \& \ HPO_4^{2-}}$ lies on either side of the desired pH of the buffer. This implies that one is slightly over and the other is slightly under.