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mestny [16]
3 years ago
5

What is the half-life of Technetium-99 if a 200 gram sample decays to 50 grams in 639,000 years?

Chemistry
1 answer:
Elenna [48]3 years ago
5 0

Answer:

The half-life of Th-232 is 1.4 ∙ 10¹⁰ years.

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Law Incorporation [45]
A is the answer ........
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Why should scientists preform experiments
svetoff [14.1K]

Answer:

To test the accuracy of a hypothesis or any findings that have already been made  

Explanation:

by performing experiments scientists get to test out any questions they have

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3 years ago
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what is the boiling point of the solution resulted from the dissolving of 32.5g of NaCl in 250.0g of water?
suter [353]

Answer:

The boiling point of this solution is 102.28 °C

Explanation:

<u>Step 1:</u> Data given

Mass of Nacl = 32.5 grams

Molar mass of NaCl = 58.45 g/mol

Mass of Water = 250 grams

Boiling point of water = 100°C

<u>Step 2: </u>Calculate number of moles

Number of moles = mass of NaCl / Molar mass of NaCl

Number of moles = 32.5 grams /58.45 g/mol = 0.556 moles

<u>Step 3:</u> Calculate molality

Molality = Number of moles / mass of water

Molality = 0.556 moles / 0.250 kg of water

Molality = 2.224 molal

NaCl releases twice as many moles of ions, the total molality of this solution is also twice: 4.448 molal

Step 4: Calculate boiling point

dT =( 0.512 C / molal)*4.448 molal)

dT = 2.28

The boiling point of this solution is 100 °C + 2.28 °C = 102.28 °C

8 0
3 years ago
Provide the correct IUPAC name for Sr(OH)2 - 7H20.
andrey2020 [161]

This question is providing us with the chemical formula of a compound whose name in IUPAC convention is strontium hydroxide heptahydrate according to the following.

<h3>IUPAC nomenclature in hydrates</h3>

In chemistry, the IUPAC allows us to assign specific names for all the chemicals in the world, in order for them to be recognized all around the world and avoid common names which differ from region to region.

Thus, for the compound we are given, we see the presence of a cationic strontium ion and an anionic hydroxide ion, both accompanied by seven molecules of water, which makes it a hydrate.

In such a way, its IUPAC name will be strontium hydroxide heptahydrate, according to the both of the ions and the number of water molecules into it.

Learn more about hydrates: brainly.com/question/919417

6 0
3 years ago
8. A party-supply store sells a helium-gas
MatroZZZ [7]

Answer:

P₂= 116.7 atm

Explanation:

Here apply the Boyle's law equations that states :at constant temperature the volume of a dry mass of a gas is inversely proportional to its pressure.

This is simplified as;

P₁V₁=P₂V₂ where P is pressure and V is volume

Given that;

P₁=1

V₁=1.81 m³

P₂=?

V₂=1.55*10^-2 m³

Apply the formula

1*1.81 =P₂*1.55*10^-2 m³

1.81/1.55*10^-2  =P₂

P₂= 116.7 atm

7 0
3 years ago
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