Iron-59 which is used to diagnose anaemia has a half life of 45days, what fraction of it is left in 90 days

Answer:

Recycling.

Explanation:

When instead of getting rid of a product you find another use for the product, it is called recycling.

Recycling can be defined as a process which typically involves gathering, processing and transformation of materials or products that would otherwise be gotten rid of as waste materials or trash into new products that could be used for another purpose.

Basically, the recycling process involves turning a trash or unwanted product into a treasure (new product) that is capable of serving another purpose.

For example, the crown cork of a bottle could be gathered and processed into art forms that can be used for decorations.

Answer:

A: Helium or Hydrogen

Explanation:

Terrestrial planets are the 4 inner most planets of the solar system which are mercury, venus, earth, Mars, while the giant planets are the 4 outer most which are Jupiter, Saturn, Uranus and Neptune.

Now, these outer most ones are the surface ones and are surrounded primarily by layers of hydrogen and helium gases.

Explanation:

1 mole = 6.02 x 10^23 atoms (Avogadro’s number)

Step 1) Determine how many grams of a substance are in the problem

Step 2) Find the amount of grams in 1 mole of the substance

3) Multiply step one by step two

Answer:

false

Explanation:

An electric field may do work on a charged particle, while a magnetic field does no work.

Answer:

1700 mL / 84 mLs

Explanation:

Given that:

Volume of blood pumped per minute = 84 /mLs

Time it takes to circulate 1700 mL of blood :

Time taken = Volume of blood circulate / Rate

Hence, to circulate 1700 mL of blood :

Time taken = 1700 mL / 84 mLs

Answer:

Released

Explanation:

they convert into a form of energy that can be used by cells

Answer:

B) The family car

Explanation:

I hope this helps :)

Answer:

37.7 atm

Explanation:

Using the relation;

(P + an^2/V^2) (V - nb) = nRT

(P + an^2/V^2) = nRT/(V - nb)

a = 0.0341 atm dm^2 Mol^2

b = 0.0237 dm/mol

P = nRT/(V - nb) - an^2/V^2

P = [4.3 * 0.082 * 325 / (3.6 - (4.3 * 0.0237))] - (0.0341 * (4.3^2))/(3.6^2)

P = 114.595/(3.498) - 0.0487

P = 37.7 atm

Answer:

Rocks are classified according to characteristics such as mineral and chemical composition, permeability, texture of the constituent particles, and particle size. This transformation produces three general classes of rock: igneous, sedimentary and metamorphic. Those three classes are subdivided into many groups.

Explanation:

Answer:

3

Explanation:

2,8,6

Answer:

65.0cp

Explanation:

Answer:

liquid

Explanation:

it's not plasma, solid, or gas

so I think liquid

Answer:

true

Explanation:

Prophase is the first stage in mitosis, occurring after the conclusion of the G2 portion of interphase. During prophase, the parent cell chromosomes which were duplicated during S phase condense and become thousands of times more compact than they were during interphase.

Answer:

That is the Atomic mass

Explanation:

The element symbol is S, Element name is sulfur, and

Atomic number is 16

Answer: The products of electrolysis are Zn(l) and [tex]Cl_2[/tex] gas

Explanation:

Electrolysis of a subastance is breaking it into its constituents by the action of electrical current.  

In the electrolysis of molten zinc chloride, zinc metal is produced at the cathode which is a negative electrode and chlorine gas produces as the anode which is a positive electrode.

[tex]ZnCl_2(l)\rightarrow Zn^{2+}+2Cl^-[/tex]

At anode : [tex]2Cl^-(l)\rightarrow 2e^-+Cl_2(g)[/tex]

At cathode : [tex]Zn^{2+}(l)+2e^-\rightarrow Zn(l)[/tex]

Answer: The vapor pressure of a solution in which the mole fraction of the solute is 0.200 is 80.0 torr

Explanation:

As the relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.

The formula for relative lowering of vapor pressure will be,

[tex]\frac{p^o-p_s}{p^o}=i\times x_2[/tex]

where,

[tex]p^0[/tex]= vapor pressure of pure solvent = 100.0 torr

[tex]p_s[/tex] = vapor pressure of solution = ?

i = Van'T Hoff factor = 1 for nonvolatile, nonelectrolyte solute

[tex]x_2[/tex] = mole fraction of solute  = 0.200  

[tex]\frac{100.0-p_s}{100.0}=1\times 0.200[/tex]

[tex]p_s=80.0torr[/tex]

The vapor pressure of a solution in which the mole fraction of the solute is 0.200 is 80.0 torr

Answer:

A. Eight

Explanation:

Although there are eight major endocrine glands scattered throughout the body, they are still considered to be one system because they have similar functions, similar mechanisms of influence, and many important interrelationships.

Answer:

Answer: When water freezes, water molecules form a crystalline structure maintained by hydrogen bonding. Solid water, or ice, is less dense than liquid water. Ice is less dense than water because the orientation of hydrogen bonds causes molecules to push farther apart, which lowers the density.

Explanation:

Answer:

3.0g remain

Explanation:

The half-life is defined as the time required for a reactant to decrease its concentration in exactly the half of the initial amount of reactant. Having this in mind:

In one half-life, the mass will be:

24.0g / 2 = 12.0g

In two half-lifes:

12.0g / 2 = 6.0g

And in three half-lifes, the mass that remain is:

6.0g / 2 =

Answer:

H^+(aq) + OH^-(aq) --------> H2O(l)

Explanation:

We must first obtain the molecular equation, the net ionic equation before we obtain the net ionic equation.

The molecular reaction equation is;

HF(aq) + NaOH(aq) -------> H2O(l) + NaF(aq)

The complete ionic equation is;

H^+(aq) + F^-(aq) + Na^+(aq) + OH^-(aq) --------> H2O(l) + Na^+(aq) + F^-(aq)

The net ionic equation is;

H^+(aq) + OH^-(aq) --------> H2O(l)

Answer:

Rate = k[NH₄OH]²

k = 6.17

Explanation:

We have concentrations of NH₄OH along with the given times. To determine the rate law of the reaction we need to determine first the order of reaction. This reaction can be order zero, first or second order. The expressions for each are the following:

Zero order:

k = [A₀] - [A] / t

First order:

k = 1/t * ln([A₀]/[A])

Second order:

k = (1/t) * (1/[A₀] - 1/[A])

And from here, the next part is easier. We just need to determine hat order is, calculating the value of k at two different times. If the value of k is constant, then we can say that the reaction is of that order.

Let's suppose its order zero (t = 1 and t = 2, [A₀] = 0.200 M):

k1 = 0.2 - 0.0895 / 1 = 0.1105

k2 = 0.2 - 0.577 / 2 = -0.1885

From this results we can conclude it's not zero order.

Let's suppose its order 1:

k1 = ln(0.2/0.0895) / 1 = 0.8041

k2 = ln(0.2/0.577) / 2 = 0.1733

It's not first order either, so we can conclude that this reaction is of 2nd order and the rate law would be:

Now that we know it's a second order reaction, we can determine the value of k using its expression:

k = (1/t) (1/[A] - 1/[A₀])

k = ln(1/0.0895 - 1/0.2) (1/1)

k = 6.17

And to confirm this value, let's calculate k for t = 2 s

k = (1/2) (1/0.0577 - 1/0.2)

The value is constant, so this is the true value of k.

Hope this helps

Answer:

the change in energy of the gas mixture during the reaction is 227Kj

Explanation:

THIS IS THE COMPLETE QUESTION BELOW

Measurements show that the enthalpy of a mixture of gaseous reactants increases by 319kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that -92kJ of work is done on the mixture during the reaction. Calculate the change of energy of the gas mixture during the reaction in kJ.

From thermodynamics

ΔE= q + w

Where w= workdone on the system or by the system

q= heat added or remove

ΔE= change in the internal energy

q=+ 319kJ ( absorbed heat is + ve

w= -92kJ

If we substitute the given values,

ΔE= 319 + (-92)= 227 Kj

With the increase in enthalpy and there is absorbed heat, hence the reaction is an endothermic reaction.

Answer:

a

Explanation:

sugar is composed of different elements combined in a manner form

Answer:

4 is the answer

Explanation:

i am not sure for this question

Answer:

The answer to this is solids!

Answer:

630.95 grams of Na₂CO₃ would be needed to produce 1000g of NaHCO₃

Explanation:

The balanced reaction is:

Na₂CO₃ + CO₂+ H₂O → 2 NaHCO₃

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:

Being the molar mass:

Then by stoichiometry the following quantities of mass participate in the reaction:

You can apply the following rule of three: if 106 grams of Na₂CO₃ are needed to produce 168 grams of NaHCO₃, how much mass of Na₂CO₃ is necessary to produce 1000 grams of NaHCO₃?

[tex]mass of Na_{2} CO_{3}=\frac{1000grams ofNaHCO_{3} *106gramsofNa_{2} CO_{3} }{168grams ofNaHCO_{3}}[/tex]

mass of Na₂CO₃= 630.95 grams

630.95 grams of Na₂CO₃ would be needed to produce 1000g of NaHCO₃

they are impacted because people loose their home due to the wreckage that has happend and landscapes are ruined due to landslides

Answer:

Well the landscape is torn up, it goes through quite a bit of damage. the plants, animals, and water are all affected by it. when a earth quake hits it destroyes most everything, houses fall into the ground and are destroyed, people die. Earthquakes destry electrical wires and many other things

Explanation:

Sorry I did not answer it full, but you can look it up online.