Can someone help me a will really appreciated. I need help fast i need someone to answer all the questions. You get 10 points

Answer:

[tex]\boxed{\text{0.56 g}}[/tex]

Explanation:

The half-life of Na-24 (15 h) is the time it takes for half of it to decay.  

After one half-life, half (50 %) of the original amount will remain.  

After a second half-life, half of that amount (25 %) will remain, and so on.  

We can construct a table as follows:  

  No. of                 Fraction          Mass

half-lives   t/da   Remaining   Remaining/g

      0             0           1                      18

       1            15            ½                    9.0

      2           30            ¼                    4.5

      3           45            ⅛                    2.2

      4           60            ⅟₁₆                   1.1

      5           75            ⅟₃₂                   0.56

      6           90           ⅟₆₄                   0.28

We see that  [tex]\boxed{\textbf{0.56 g}}[/tex] remain after five half-lives (75 h).

The half-life of Sodium-24 is 15 hours. Using this information, you can determine that approximately 0.5625g of the initial 18g of Sodium-24 will remain after 75 hours.

In order to determine the amount of Sodium-24 remaining after 75 hours, we first need to know the half-life of Sodium-24, which is approximately 15 hours. The term 'half-life' refers to the period of time it takes for half of the initial amount of a radioactive substance to decay.

After one half-life (15 hours), half of the 18g of Sodium-24 would remain, which is 9g. After the second half-life (30 hours), half of the 9g would remain, which is 4.5g. After the third half-life (45 hours), half of 4.5g would remain, which is 2.25g. After the fourth half-life (60 hours), half of 2.25g would remain, which is about 1.125g. Finally, after the fifth half-life (75 hours), half of 1.125g would remain, which is approximately 0.5625g. Thus, after 75 hours, 0.5625g of the initial 18g of Sodium-24 would remain.

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N(number of moles)=mass/molar mass

10.5=mass

Na=23 (rounded)

Cl=36 (rounded)

Add it together to get the molar mass

=59

Then refer back to the formula

10.5/59

=0.17796

Round that answer

=0.18 mol

Answer : The correct option is, 0.180 mole

Explanation : Given,

Mass of NaCl = 10.5 g

Molar mass of NaCl = 58.5 g/mole

Formula used :

[tex]\text{Moles of NaCl}=\frac{\text{Mass of NaCl}}{\text{Molar mass of NaCl}}[/tex]

Now put all the given values in this formula, we get the moles of NaCl.

[tex]\text{Moles of NaCl}=\frac{10.5g}{58.5g/mole}[/tex]

[tex]\text{Moles of NaCl}=0.179mole=0.180mole[/tex]

Therefore, the number of moles of NaCl is, 0.180 mole

The answer to this question would be b.

3 things affect the freezing point of water, a constant(Kf), molality(b) and a number of dissolved particles (i).

Kf is a constant so that has the same effect. Because you have 1 mole of everything, molality is also constant.

so the only thing you gotta look after is the number of the dissolved particles which which iron III chloride has the highest

Final answer:

The 1 molar FeCl3 solution will have the lowest freezing point because, upon dissociation, it produces the most particles per kilogram of water, which causes the greatest freezing point depression. So the correct option is b.

Explanation:

The solution with the lowest freezing point is determined by the number of particles produced in the solution upon dissolving the solute. The effect on the freezing point is a colligative property, meaning it depends on the number of solute particles in the solution, not the type of particles. To answer which of the following solutions will have the lowest freezing point — 1 molar KCl, 1 molar FeCl3, 1 molar CaCl2, or 1 molar NaCl — we must consider the dissociation of each compound.

KCl, NaCl, and CaCl2 are all salts that dissociate into ions in solution. KCl and NaCl dissociate into two ions (K+ and Cl- for KCl, Na+, and Cl- for NaCl), so a 1 molar solution of these salts will produce 2 moles of ions per kilogram of water. CaCl2 dissociates into three ions (Ca2+, Cl-, Cl-), resulting in 3 moles of ions per kilogram of water. FeCl3, however, dissociates into four ions (Fe3+, Cl-, Cl-, Cl-), which gives us 4 moles of ions per kilogram of water.

Thus, the solution of 1 molar FeCl3 will have the lowest freezing point because it produces the highest number of dissociated particles, leading to the greatest degree of freezing point depression.

I am pretty sure the answer is D. Lithospheric plate movement. :)

D, because without plate movement, there would be no earthquakes or other geologic events.

Answer:

This reaction is an example of forming ester "Esterification".

Explanation:

Ethanol + acetic acid → ethyl-ethanoate + water.

C₂H₅OH + CH₃COOH → CH₃COOC₂H₅ + H₂O.

Answer:

Chernobyl Accident 1986. The Chernobyl accident in 1986 was the result of a flawed reactor design that was operated with inadequately trained personnel. The resulting steam explosion and fires released at least 5% of the radioactive reactor core into the atmosphere and downwind – some 5200 PBq (I-131 eq).

Explanation:

The Chernobyl disaster was a catastrophic nuclear accident in 1986, causing immediate deaths and long-term health issues due to radiation. The region remains largely uninhabitable due to persistent contamination.

Significance of the Chernobyl Meltdown:

The Chernobyl disaster, which occurred on April 26, 1986, was a catastrophic nuclear accident at the Chernobyl Nuclear Power Plant in Ukraine. During an unauthorized safety test, reactor no. 4 exploded due to an uncontrollable chain reaction, causing immense steam pressure that ruptured the reactor and released radioactive material.

The aftermath saw 50 tonnes of radioactive material released into the environment, leading to the evacuation of approximately 30,000 people.

Immediate effects included the deaths of 32 plant workers and firefighters who succumbed to acute radiation sickness. Long-term consequences predict around 4000 additional deaths from radiation-induced illnesses like cancer among emergency workers and former residents.

The region around Chernobyl remains highly contaminated and largely uninhabitable, demonstrating the devastating and lasting impact of nuclear accidents on both human populations and the environment.

The Chernobyl disaster has highlighted the risks associated with nuclear energy, influenced global nuclear policy and safety standards, and left a stark reminder of the potential outcomes of nuclear energy mismanagement.

Answer:

The correct answer option is a) collisions between the particles and surrounding molecules.

Explanation:

The collisions between the particles and surrounding molecules causes the Brownian motion of particles in a colloid.

Brownian motion is the irregular movement of the microscopic particles in a fluid which bombard into each other.

It basically is the result of the molecules of a dispersion medium colliding with the dispersed particles of the phase.

Answer:

0.9925 atm.

Explanation:

We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm (P = ??? atm).

V is the volume of the gas in L (V = 42.5 L).

n is the no. of moles of the gas in mol (n = 1.52 mol).

R is the general gas constant (R = 0.0821 L.atm/mol.K),

T is the temperature of the gas in K (T = 65°C + 273 = 338.0 K).

∴ P = nRT/V = (1.52 mol)(0.0821 L.atm/mol.K)(338.0 K)/(42.5 L) = 0.9925 atm.

Answer:

The correct answer is radiation thermal energy.

Explanation:

The transfer of energy in thermal energy comprises the transfer of internal energy. The three kinds of thermal energy transfer are convection, conduction, and radiation. In convection, the movement of warm particles takes place, in conduction the direct contact of atoms occurs, and in radiation, the transfer of energy takes place in the form of electromagnetic waves.

A balanced chemical equation is analogous to a recipe because it outlines precise quantities of reactants needed to produce specific products, reflecting the concept of stoichiometry used in cooking. Adjusting ingredient amounts when changing recipe size is similar to calculating reactant and product amounts in chemical reactions, demonstrating the conservation of mass.

A balanced chemical equation is similar to a recipe in that both provide the exact proportions of ingredients or reactants needed to produce a desired outcome, be it a chemical product or a food dish. When you follow a recipe, you are essentially performing stoichiometry, which is the precise measurement and calculation of reactants and products in a chemical reaction. Just as doubling or halving a recipe requires adjusting the amount of each ingredient accordingly, the same concept applies to chemical reactions when predicting the amounts of products produced or reactants required.

For instance, just like a recipe that makes 1 dozen biscuits requires specific quantities of flour, eggs, shortening, salt, baking soda, and milk, a chemical equation needs to balance the atoms of each element on both the reactant and product sides of the equation. This reflects the conservation of mass, as the quantity of each element remains constant throughout the reaction. The balanced equation thus communicates not only the substances involved but also their amounts in a concise and quantitative manner. By understanding the concepts used in cooking, one can grasp the principles of stoichiometry and balanced equations in chemistry.

Answer:

Kindly find the attached image.

Explanation:

Activation energy: is the difference in potential energy between the activated complex and reactants.

Enthalpy of  reaction: is the difference in potential energy between the products and reactants.

Answer : The energy diagram is shown below.

Explanation :

Activated complex : When the reactant molecules absorb energy then their bonds are loosened and new lose bonds are formed between them.

The intermediate formed is known as activated complex and it is an unstable state and immediately dissociates to form the stable products.

Activation energy : It is defined as the minimum amount of energy absorbed by the reactant molecules so that their energy becomes equal to the threshold energy. Or we can say that, the difference between the reactant and the activated complex.

Enthalpy of reaction : It is defined as the energy change that takes place when the reactants go to the products. It is represented as, [tex]\Delta H[/tex]. Or we can say that, the difference between the product energy and the reactant energy.

Hence, the energy diagram is shown below.

Answer:

12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms.

Explanation:

Using a balanced chemical equation we can identify the number of carbon, hydrogen, and oxygen atoms in sugar.

CxHyOn + 12O₂  → 11 H₂O + 12CO₂

when an equation is completely balanced, then the number of each atom of an element is equal on the reactant side and the product side.

Therefore;

For carbon; x = 12

For Hydrogen; y = (11×2) = 22

For Oxygen; n + (12×2) = 11 + (12×2)

                    = n + 24 = 11 + 24

                        n = 11

Therefore the sugar has, 12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms.

Thus the balanced equation would be;

C₁₂H₂₂O₁₁ + 12O₂  → 11 H₂O + 12CO₂

Answer:

12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms.

Explanation:

Answer:

2.209687527979228

Explanation:

Hope this help!

Answer:

[tex]\boxed{\text{A) filter}}[/tex]

Explanation:

An automobile air filter is often made of porous pleated paper. Many of them are cylindrical, as in the diagram below, but others have shapes that fit the available space in the engine compartment.

B) is wrong. A radiator is used to cool the car's engine.

C) and D) are wrong. You probably won't find a distillation apparatus or chromatography paper in your mother's car unless she is a chemist taking them somewhere else.

It would be letter A

Pluto was ruled not a planet anymore because it is a "dwarf  planet"

Apparently, the International Astronomical Union's (IAU) definition of a planet includes that a planet should be part of a body that would orbit the sun.  

According to the IAU, there are three criteria's that contribute to a planet being called a planet.

1. It is within orbit around the Sun.

2. It has a sufficient mass to assume a nearly round shape

and 3. It has "cleared the neighborhood" around it's orbit.

Pluto only so happens to meet 2 of these requirements, not including the third option.

Answer:

In august 2006 the international astronomical union (IAU) downgraded the status of Pluto to that of "Dwarf planet." this means that from now on only the rocky worlds of the inner solar system and the gas giants of the outer system will be designated.

("Hope this is helpful.")

Answer:

The molecules have shorter inter molecular distances  and less kinetic energy than the original gas sample.

The cooling reduces the kinetic energy of the gas sample and thus the molecules making up the liquid sample travel less distances due to the less energy. The less inter molecular distances increases the attraction due to inter molecular forces packing the molecules near each other, forming a liquid.

-173.15

-0.15

-267.15

416.15

846.15

assuming k is kelvins and c is celsius

1. -173.15°c

2. -0.15°c

3. -267.15°c

4. 416.15k

5. 846.15k

Answer: compound, chemical

Explanation:

Answer:

it explains the relationship between temperature and volume

Charles law states that if given quantity of gas is held at a constant pressure, then its volume is directly proportional to the absolute temperature. this law explains relation between temperature and volume.

Charles' law is just a gas statement that governs how gases increase while heated in an experimental setting. The Kelvin temperature and volume should be in direct proportion whenever the pressure on such a test of dry gas was maintained constant, according to a modern version of Charles's law.

A scalar quantity that expresses the proportion of three-dimensional area contained by a sealed surface will be called volume.

Therefore, Charles law states that if given quantity of gas is held at a constant pressure, then its volume is directly proportional to the absolute temperature. this law explains relation between temperature and volume.

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Answer:

In order to answer the question, we convert the measurements given to a common base unit. For this case, we use seconds.

A)   0.02 seconds

B)   0.02 teraseconds x (10^12 s / 1 terasecond) = 2x10^10 seconds

C)   2,500 milliseconds x (1 s / 1000 ms) = 2.5 seconds

D)   25,000 nanoseconds x (1 x 10^-9 s / 1 nanosecond) = 2.5 x 10^-5 seconds

So ,The correct answer is option " D "

I believe C is the balanced equation.

C is the answer i think

Answer:

CH2.

Explanation:

The mass of C in the CO2 =  2.49 * 12/(12+32) =  0.6791 g

The mass of Hydrogen in the water = 2 * 1.008 / (2.016 + 16) = 0.1119 g.

Ratio of H to O is 0.1119/ 1.008 : 0.6791/12

= 0.111 : 0.0566

= 2 : 1

The empirical formula is CH2

Ans: 187.5 grams of Al2O3

Final answer:

To calculate the mass of [tex]Al_2O_3[/tex] produced from 375 grams of Al, we find the moles of Al, use the stoichiometry of the reaction to find the moles of [tex]Al_2O_3[/tex], and then convert to grams. The result is 708.6 grams of [tex]Al_2O_3[/tex].

Explanation:

Given the balanced chemical reaction [tex]4Al + 3O_2 \rightarrow 2Al_2O_3[/tex], we first need to calculate the number of moles of aluminum (Al) that's present in 375 grams. Using the molar mass of aluminum (26.98 g/mol), we can determine this:

Hence, if 375 grams of Al react completely, a total of 708.6 grams of [tex]Al_2O_3[/tex] will be produced.

-Hello There-

When red light is added to green light you get yellow

Answer:

It completely dissociates in water.

Explanation:

The characteristic of a strong acid is that it completely dissociates when dissolved in water to form ions.

Acids are defined as substances which on dissociation yield H+ ions , and these substances are sour in taste. Compounds such as  HCl, H₂SO₄ and HNO₃ are acids as they yield H+ ions on dissociation.

According to the number of H+ ions which are generated on dissociation acids are classified as mono-protic , di-protic ,tri-protic and polyprotic  acids  depending on the number of protons which are liberated on dissociation.

Acids are widely used in industries  for  production of fertilizers, detergents  batteries and dyes.They are used in chemical industries for production of chemical compounds like salts which are produced by neutralization reactions.

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Answer:

the answer would be C:  point source

Explanation:

because it specified the source of the pollution (manufacturing plant)

Answer:B.)

Explanation:

what the other person said

Answer:

D

Explanation:

All the others are unrelated to biology as biology is the study of life (hence bio) and not chemistry or anything else.

A biologist might study the causes of honeybee deaths in beehives, as it falls within the biological study of organisms, their ecosystems, and their interaction with the environment. Ecologists, as biologists, may study predator-prey dynamics and the role of biodiversity and ecological succession in species survival.

A biologist might choose to study the causes of honeybee deaths in beehives. This topic falls under the field of biology as it involves examining the biological factors, ecosystems, and environmental impacts on a species. Biology encompasses the study of living organisms, their interactions within ecosystems, and factors affecting their survival. For instance, a biologist studying honeybee mortality may investigate patterns in bee behavior, health, genetic factors, or the influence of pesticides and other anthropogenic factors on populations.

A specific example of a biologist's work could be an ecologist studying the patterns on the wings of an endangered butterfly species to understand how these patterns help the species escape predators like birds. Researchers in such fields collect data, observe, and analyze patterns to draw conclusions about biological processes and biodiversity. Additionally, factors such as ecological succession and biogeography are critical in such studies.

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The law of inertia. Basically, every object stays in the same spot unless they are moved by an external force, .

An object at rest will remain at rest or an object in motion will remain in motion unless acted upon an unbalanced force

Energy is released when this happens

I believe it is Energy, I am not sure. Sorry if it is wrong.