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2 years ago

Help please science (7th grade)

Chemistry

2 answers:

hoa [83]2 years ago

8 0

Answer:

Explanation:

Don't mind the random letters

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tiny-mole [99]2 years ago

8 0

Answer:

Explanation:

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Iridium has only two naturally occurring isotopes. Ir-191 with arelative mass of 190.96058 and Ir-193 with a relative mass of192

OLEGan [10]

Answer: The fractional abundance of Ir-191 is 0.372

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ .....(1)

Let the fractional abundance of Ir-191 be x and that of Ir-193 isotope be (1-x)

For isotope 1 (Ir-191):

Mass of isotope 1 = 190.96058 amu

Fractional abundance of Ir-191 = x

For isotope 1 (Ir-193):

Mass of isotope 1 = 192.96292 amu

Fractional abundance of Ir-193 = (1 - x)

Average atomic mass of iridium = 192.217 amu

Putting values in equation 1, we get:

$192.217=[(190.96058\times x)+(192.96292\times (1-x))]\\\\x=0.372$

Hence, the fractional abundance of Ir-191 is 0.372

6 0

3 years ago

a balloon has a pressure of 104.5 kpa and a volume of 3.4L. If the pressure is reduced to 42.7 kpa, what will the volume change

Nuetrik [128]

Answer:

The answer to your question is 8,32 L

Explanation:

Data

Pressure 1 = 104.5 kPa

Volume 1 = 3.4 L

Pressure 2 = 42.7 kPa

Volume 2 = ?

Formula

- To solve this problem use the Boyle's law.

P1V1 = P2V2

- Solve for V2

V2 = P1V1 / P2

- Substitution

V2 = (104.5)(3.4) / 42.7

-Simplification

V2 = 355.3 / 42.7

- Result

V2 = 8.32 L

7 0

3 years ago

Read 2 more answers

For pea plants, T represents a dominant allele for tall pea plants and t is the recessive allele for short pea plants. If two pl

myrzilka [38]

75% (TT,Tt,Tt,tt) hope that helps :)

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3 years ago

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(Please help ASAP I will mark brainliest!! (: )Which of the following describes what happens when a cell uses energy to transpor

mr Goodwill [35]

Answer: 4. Active Transport

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3 years ago

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To breed or train; to tame a wild animal to live with humans.

Ierofanga [76]

Answer:

The answer is to train.

Explanation:

Training is another word for taming a wild animal. To breed is to take to animals and make them have offspring with each other.

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3 years ago