Rosina creates a demonstration showing a sound echo. How could she demonstrate this? She throws water at a wall, and it drips down the wall,
B She throws a rubber ball at a wall, and it bounces back to her,
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She throws an egg at a wall, and it breaks and falls to the floor,
D She throws sand at a wall, and it hits the wall and falls to the floor.

correct option for this question is B. when he throw rubber ball at a wall and it bounce back to her

b rubber ball

Explanation:

it will bounce back not like the other things she threw

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.

hey there!

mass = 6.75 g

volume =   9 cm³

therefore:

d = mass / volume

d   = 6.75 / 9

d = 0.7 g/cm³

answer b