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2 years ago

Phosphorus-33 has a half-life of 25 days. What fraction of the original sample would remain after 300 days?

Chemistry

1 answer:

zloy xaker [14]2 years ago

6 0

Answer:

The correct answer is - 1/4096.

Explanation:

In the starting, there is that the number of atoms is N 0 .

The number of half-lives in this case, = 300/ 25 = 12

After the first half-lives or 25 days, N 1 = N 0 /2

the half life is that time where half of the sample had decay.

After the second half-life or 50 days, N 2 = N 1 /2 = N 0 /4 .

There is division by two the original amount, then after four times you divide four times for 2 that means that you divide by 2 ^12 =4096 .

So the final amount remain is N 12 = N 0 /4096 or 1/4096.

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Cells are made of many parts, or , that help the cell do its job. Each cell organelle has a specific function, or

MakcuM [25]

Answer:

Organelles; role.

Explanation:

A cell can be defined as the structural, fundamental, biological and functional unit of life. Cells are found in all living organisms because they are the basic unit of life. A unicellular organism refers to a living organism that possess a single-cell while a multicellular organism has many (multiple) cells. Generally, cells have the ability to independently replicate themselves. In a cell, the "workers" that perform various functions or tasks for the survival of the living organism are referred to as organelles. Some examples of cell organelles with their respective functions in all living organisms such as trees, birds, and bacteria include;

1. Nucleus : it controls all the activities taking place in the cell and the synthesis of proteins.

2. Mitochondria : it provides all the energy required in the cell by transforming energy forms.

3. Lysosomes : they are responsible for absorbing materials and breaking the materials taken in by the cells.

4. Chromosomes : they give sets of instructions for the synthesis of products.

5. Ribosomes : they are involved in the build up of proteins.

6. Endoplasmic Reticulum : this is where the ribosomes perform their tasks.

7. Cytoskeleton : they help to maintain and support the shape of the cells.

8. Vesicles : they ensure proteins are properly transported to the right and exact location.

9. Golgi apparatus : it prepares the protein for export by chemically tagging them.

10. Cell membrane : is the wall of the cell and typically controls what leaves and enters the cell.

Hence, cells are made of many parts, or organelles, that help the cell do its job. Each cell organelle has a specific function, or role.

4 0

3 years ago

A system was prepared with NH3 = O2 = 3.60 M as the only components initially. At equilibrium N2O4 is 0.60M. Calculate the value

frozen [14]

Answer:

Kc = 0.0216

Explanation:

To do this, we need to write the equilibrium reaction which is the following:

NH3 + O2 <------> N2O4 + H2O

And now, let's balance the equation

4NH3 + 7O2 <--------> 2N2O4 + 6H2O

The general expression for Kc is:

Kc = [N2O4]²[H2O]⁶ / [O2]⁷[NH3]⁴

Now, in order to know the concentrations, we need to do an ICE chart here, so we can know the final concentrations of all species here:

4NH3 + 7O2 <--------> 2N2O4 + 6H2O

I: 3.6 3.6 0 0

C: -4x -7x +2x +6x

E: 3.6 - 4x 3.6 - 7x 0.6 +6x

According to this, we know that N2O4 is 0.6M, but in the change we have that it gained 2x so the value of x will be:

2x = 0.6

x = 0.6/2 = 0.3

Therefore, the value of x is 0.3 ans we can know now the concentrations of all species in equilibrium, and then, the kc:

[NH3] = 3.6 - 4(0.3) = 2.4 M

[O2] = 3.6 - 7(0.3) = 1.5 M

[H2O] = 6(0.3) = 1.8 M

Now the value of Kc would be:

Kc = (0.6)² (1.8)⁶ / (2.4)⁴ (1.5)⁷

Kc = 0.0216

8 0

3 years ago

Who founded the terrorist organization al-Qaeda?

oksano4ka [1.4K]

Osama Bin Laden founded the terrorist organization Al- Qaeda. The correct option to the given question is option "C". <span>Osama Bin Laden was born on 10th March in the year 1957 in Riyadh of Saudi Arabia. He died or rather was killed on 2nd May 2011 in Abbottabad of Pakistan. Osama was born in a billionaire family and his father’s name was Mohammad Bin Awad bin Laden. He was a fierce terrorist and had connections with several terrorist organizations around the world. </span>

3 0

3 years ago

Identify the precipitation reaction in the set?

Harlamova29_29 [7]

Answer:

The third reaction

(2NaOH + NiCL2 ---> 2NaCl + Ni(OH)2)

Explanation:

By definition, a precipitation reaction refers to the formation of an insoluble salt when two solutions containing soluble salts are combined.

(Source: lumenlearning)

From the 4 options, we can eliminate the first and second one immediately because there is no formation of an insoluble salt.

Then, the last one can also be eliminated because even though there is insoluble solid formed, but it is not a salt, and, the reactants are not solutions too. In fact, the last one is a displacement reaction. A more reactive metal displaces a less reactive metal to form an ion.

Since the third reaction matches the definition of precipitation reaction, this is the answer.

4 0

3 years ago

Consider the reaction of cyclohexanol and an acid catalyst to obtain cyclohexene.

amid [387]

Answer : The percent yield of the reaction is, 86.5 %

Solution : Given,

Mass of Cyclohexanol = 3.1 g

Molar mass of Cyclohexanol = 100.16 g/mole

Molar mass of Cyclohexene = 82.14 g/mole

First we have to calculate the moles of Cyclohexanol.

$\text{ Moles of Cyclohexanol }=\frac{\text{ Mass of Cyclohexanol }}{\text{ Molar mass of Cyclohexanol }}=\frac{3.1g}{100.16g/mole}=0.03095moles$