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2 years ago

2. Mercury-197 is used for kidney scans and has a half-life of 3 days. If 32 grams of

Chemistry

1 answer:

VLD [36.1K]2 years ago

8 0

<h3>Answer:</h3>

1 grams Mercury-197

<h3>Explanation:</h3>

From the question,

The radioisotope is Mercury-197

The half life of Mercury-197 is 3 days

Starting mass is 32 grams

Time taken is 15 days

We are required to calculate the final mass of the radioisotope after 15 days.

Note that, half life is the time taken by radioisotope to decay by half its original amount.
In this case, the half life of mercury-197 is 3 days, therefore, it takes three days for a mass of mercury-197 to decay by half its original mass.

Therefore, using the formula;

Final amount = Starting mass × (1/2)^n

where n is the number of half-lives (ratio of time to half life)

In our case, n = 15 days ÷ 3 days

= 5

Therefore;

Final mass = 32 g × (1/2)^5

= 32 g × 1/32

= 1 g

Therefore, the amount of mercury-197 in the shipment that will arrive is 1 g.

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Write the name of the alkyne next to the drawing of the molecule. (2 points)

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1) 1-Pentyne

2) But-2-yne

3) Ethyne

4) 1-Propyne

5) 1-Butyne

6) Pent-2-yne

<h3>What is alkyne?</h3>

Molecules that contain a triple bond between two carbon atoms are known as alkynes.

1) The number of carbon on the longest chain = 5, (two carbon atoms between the triple bond) therefore the prefix is pen-

The functional group is the triple bond on the first carbon with the suffix -yne

The name of the compound is 1-Pentyne

2) There are 4 carbon atoms on the longest chain, therefore, the prefix is but-

The location of the triple bond functional group (suffix; -yne) is on the second carbon atom

Therefore, the name of the compound is But-2-yne

3) The triple bond functional group is between the only two carbon atoms, therefore, the name is Ethyne

4) The number of carbon atoms = 3, with a prefix prop-, and the functional group on the first carbon atom on the longest chain is the triple bond, with suffix -yne

Therefore, the name of the compound is 1-Propyne

5) The number of carbon atoms on the longest chain = 4, the prefix is but-

The location of the triple bond functional group (suffix -yne) is on the first carbon atom

Therefore, the name is 1-Butyne

6) The number of carbon atoms on the longest chain = 5, the prefix of the compound is pen-

The location of the triple bond functional group (suffix; -yne) is on the second carbon atom, therefore;

The name of the compound is Pent-2-yne

Learn more about alkyne here:

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2 years ago

PLEASE HELP QUICK!! WILL MARK BRAINLIEST ANSWER!! When water is diffused across a selectively permeable membrane, scientists ref

xxTIMURxx [149]

Answer :

During diffusion, when the concentration of the molecules on both sides of the membrane is the same, the molecules will continue to move across the membrane in both the direction.

Answer 3 : It allows single-celled organism to reproduce, and other organism to repair damage tissues and grow.

Answer 4: The nucleus is an organelle that is surrounded by the cytoplasm, a jelly-like fluid.

Explanation :

Diffusion : It is a process where liquid moves from higher concentration to the lower concentration through permeable membrane.

When the concentration of the molecules on both sides of the membrane is same and the membrane is permeable membrane then diffusion will occur and the molecules will moves continuously across the membrane in both the direction.

Answer 3 :

Mitosis : It is a process of cell division. In this process, nucleus divides into two daughter cell and each daughter cell contains same number of chromosomes as present in parent nucleus.

The main purpose of the mitosis is to repair damaged tissues and growth.

Answer 4 :

Nucleus is a type of cell organelle. It is present in both animal and plant cells and it is the brain of the cell. It is present only in eukaryotic cell.

Nucleus is an organelle which is surrounded by the cell membrane which protects its from the other cells.

Cytoplasm is a jelly-like fluid which is present in the cell membrane which is made up of salt and water.

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2 years ago

Ammonium nitrate is an ingredient in cold packs used by sports trainers for injured athletes. Calculate the change in temperatur

Ronch [10]

Answer:

See explanation

Explanation:

First, we need to use the correct expression:

Q = m*Cp*ΔT (1)

Q = n*ΔH (2)

These are the 2 expressions to calculate heat or energy.

Now, we want to know the change of temperature of the nitrate in water after being added, so with the innitial data of nitrate, we can calculate heat using the second expression. First, we need to calculate moles with the molecular mass:

n = m/MM

n = 42/80.1 = 0.52 moles

With these moles, we can calculate heat with the ΔH of this reaction:

Q = 0.52 * 25.7 = 13.364 kJ or 13,364 J

However, this heat as is being absorbed, the value would be negative.

Now that we have heat, we can use expression (1) and plug these values to solve for ΔT, but before, we need to know the total mass of the solution (water + nitrate)

m = 250 + 42 = 292 g

now, solving for ΔT:

-13,364 = 292 * 4.18 * ΔT

ΔT = -13,363 / (292 * 4.18)

ΔT = -10.95 °C

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2 years ago

What is the mass of an atom with 8 protons, 8 electrons, and 8 neutrons?

mafiozo [28]

Answer:An oxygen atom usually has 8 protons, 8 neutrons, and 8 electrons. Looking at the periodic table, oxygen has atomic number 8 and atomic weight 15.999.

Explanation:

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2 years ago

Calculate the % composition of the unknown liquid using your most precise result. It is a mixture of ethanol (D[ETOH] = 0.7890 g

Rufina [12.5K]

% composition of ethanol = 34.51%

% composition of water = 65.49%

<h3>What is density?</h3>

A material's density is defined as its mass per unit volume.

Given data:

The density of ethanol = 0.7890 g/mL

The density of water = 0.9982 g/mL