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2 years ago

The Half-Life of Pa-234 is 6.75 hours. How much (what fraction) of a sample of this isotope remains after 20.25 hours?

1 answer:

6 0

So in one hour half the amount remains (that's what half life means). In two hours 1/4 (or half of half) would remain and in three hours 1/8 would remain.
So the answer is 1/8

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Please help me if possible<br>

Gwar [14]

Explanation:

RAM={mass number ×relative abundance (%) + mass number ×relative abundance (%)} ÷100%

so take (91.05×20) +(8.95×22)

5 0

1 year ago

What would be the pH of an H2SO4 solution if the [H+] = 4.58 x 10-5 moles/liter?

Ghella [55]

Answer: pH of an $H_2SO_4$ solution is 4.34

Explanation:

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration.

$pH=-\log [H^+]$

$H_2SO_4\rightarrow 2H^++SO_4^{2-}$

Putting in the values:

$pH=-\log[4.58\times 10^{-5}]$

$pH=4.34$

Thus pH of an $H_2SO_4$ solution if the $[H^+]$ is $4.58\times 10^{-5}]$ is 4.34

4 0

2 years ago

Which of the compounds below will ionize in

-BARSIC- [3]

I need help on this one

5 0

1 year ago

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Explain what might happen to tundra animals, such as polar bears, as earth's climate warms. pls explain

SCORPION-xisa [38]

Answer:

They will die.

Explanation:

Polar Bears were made to live in the frigid temperatures of the tundras. If there is a temperature change it can affect their habitat. It can destroy it and they would have to move out to another place. They can die due to global warming.

8 0

2 years ago

You have a 5-liter container with 1.30×10^24 molecules of ammonia gas (NH3) at STP.

givi [52]

Answer:answer is C

Explanation:

3 0

2 years ago

Read 2 more answers