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Tomtit [17]
3 years ago
11

Strontium 90 (sr-90, a radioactive isotope of strontium, is present in the fallout resulting from nuclear explosions. it is espe

cially hazardous to animal life, including humans, because, upon ingestion of contaminated food, it is absorbed into the bone structure. its half-life is 27 years. if the amount of sr-90 in a certain area is found to be four times the "safe" level, find how much time must elapse before the safe level is reached.
Chemistry
1 answer:
Artyom0805 [142]3 years ago
7 0
This is a relatively easy half-life problem.
Whenever a half-life has expired, one half of the radioactive isotope will no longer be present.
When 2 half-lives have occurred, then one quarter of the isotope remains.
Therefore, the strontium - 90 will be at a safe level in 54 years.
 

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Given the formula representing a compound: what is a chemical name of this compound? 2-pentene 2-pentyne 3-pentene 3-pentyne
Aleks [24]
The question is incomplete. Complete question is attached below.
..........................................................................................................................

Correct Answer: <em>Option 1) 2-pentene</em>

Reason:
Following are the IUPAC rules for naming the compound
1) Select the longest carbon chain. In present case longest carbon chain has 5 carbon atom. Hence, it is a pentane derivative.
2) In case of alkene, replace 'e' of alkane by 'ene'
3) Give lowest number to function group. In present case, it is double bond.

Applying above rules, the IUPAC name of compound is 2-pentene

4 0
3 years ago
A gas cylinder initially contains 463 L of gas at a pressure of 159 atm. If the final volume of gas is 817 L, what is the final
Agata [3.3K]

Answer:

The final pressure is 90.1 atm.

Explanation:

Assuming constant temperature, we can solve this problem by using <em>Boyle's Law</em>, which states:

  • P₁V₁=P₂V₂

Where in this case:

  • P₁ = 159 atm
  • V₁ = 463 L
  • P₂ = ?
  • V₂ = 817 L

We <u>input the given data</u>:

  • 159 atm * 463 L = P₂ * 817 L

And <u>solve for P₂</u>:

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The final pressure is 90.1 atm.

6 0
3 years ago
The process that splits rock through freezing and thawing is called?
maw [93]
It's called Ice Wedging :)
8 0
4 years ago
Read the following chemical equation
Naddika [18.5K]

Answer:

For eacht 4 moles Fe consumed, we will produce 2 moles Fe2O3

The mole ration is 4:2 (option 1)

Explanation:

Step 1: The unbalanced equation

Fe + O2 → Fe2O3

Step 2: Balancing the equation

Fe + O2 → Fe2O3

On the left side we have 2x O (in O2) and on the right side we have 3x O (in Fe2O3) . To balance the amount of O on both sides, we have to multiply O2 by 3 and Fe2O3 by 2.

Fe + 3O2 → 2Fe2O3

On the left side we have 1x Fe, On the right side we have 4x (in 2Fe2O3). To balance the amount of Fe we have to multiply Fe (on the left side) by 4.

Now the equation is balanced.

4Fe + 3O2 → 2Fe2O3

For eacht 4 moles Fe consumed, we will produce 2 moles Fe2O3

The mole ration is 4:2 (option 1)

8 0
4 years ago
An FM radio station broadcast at a frequency of 98.5 MHz. What is the wavelength of the station’s broadcast signal?
Troyanec [42]

Answer:

(1 MHz = 106 s -1)

Explanation:

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