If the amount of radioactive iron-59 in a sample prepared for study of iron metabolism in the spleen decreases from 1.6 g to 0.40 g in 84.0 days, what is the half-life of iron-59?

Answer:

One mol of NaCl (6.02 x1023 formulas) has a mass of 58.44 g

Explanation:

Molar mass of Nacl=23+35.5=58.5g

\(mole = \frac{given \: mass}{molar \: mass} \\ mole = \frac{12.25}{58.5} \\ mole = 0.21\)

BRAINLIST

Molar mass is an intensive property of a sample of water.

The molar mass of a certain chemical entity is its mass per unit quantity (symbol M, SI unit kgmol1). Always identify the chemical in question in accordance with the definition of the mole. A substance's molar mass is the volume of the material that contains one mole of the substance. Its basic definition is the weight of a single mole of a substance. The atomic mass of each substance is multiplied by the subscript of that element in the chemical formula to determine the molar mass.

One mole of a specific compound or material has a mass of 1 molar. We are aware that the number of moles in a compound (n) can be expressed as the ratio of the compound's  given mass to its molar mass. This is measured in g mol1, the standard unit. However, the SI unit, kg mol 1, is quite uncommon. The amount of particles in 1 mole of the substance is equal to the number of atoms present in 12g of the 12C isotope.

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Answer:

The dependant variable

Explanation:

The dependent variable is the factor that is being tested and measured in an experiment.

Answer:

C. 10

Explanation:

So wr for protons is 2 and wr for alpha particles is 20. In these terms, alpha particles cause ten times more damage then protons.

10 times more dangerous are alpha particles than protons. The correct option is C. 10.

Radiation is emission or transmission of energy in the form of waves.

The waves are electromagnetic waves, infrared rays, x- rays, ultraviolet rays, etc.

Thus, the correct option is C, 10.

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Answer:

drought

Explanation:

on edge 2021

Answer:

drought

Explanation

its right on edge

Answer:Nitrogen gas

Explanation:

I believe it is nitrogen correct me if i am wrong.

Answer:

heterogeneous mixture.

Explanation:

Fog is heterogeneous mixture of water, air and suspension particles.

Answer:

4.7485 g

Explanation:

4.50 x 10^22 Cu atoms * (1 mol Cu / 6.022 x 10^23 Cu atoms) * 63.546 g Cu/(mol Cu) = 4.7485 g

In every mole of Cu, there are 6.022 x 10^23 atoms (Avogadro's number). The molecular weight of copper is 63.546 g/mol.

Answer:

thanks

Explanation:

The Voltage is the pressure from the electrical circuit of the power source that passes the current.

The Voltage is defined as the pressure from the electrical circuit of the power source that will passes the charged electrons that is the current through the conducting loop, it will enable them to do work  because of the illuminating the light. The in simple terms is : voltage = pressure, and it is denoted as the volts and the symbol is the V.

The voltage is described as the force that causes the flow of the charged particles. The Voltage is also called as the electromotive force.

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Answer:

The correct answer would be = 0.1593 mCi.

Explanation:

The initial 123I = 2.55 mCi (given)

We know that the half-life of radioactive I-123 =  12 hours approximately.

So, we can say that in 48 hours there will be four half-lives of 123I,

Hence after four half-life or 48 hours, the final 123I would be:

= 2.55 * (1/2⁴)

= 2.55 * (1/16)

= 0.1593 mCi

Thus, the correct answer would be = 0.1593 mCi.

The enthalpy of the reaction is  -30.4 kJ/mol

Enthalpy change refers to the amount of heat released or absorbed by a system at constant pressure during a chemical reaction or a physical process. It is denoted by the symbol ΔH and is measured in units of joules (J) or kilojoules (kJ).

If the enthalpy change is negative (ΔH < 0), it means that the reaction or process is exothermic, which implies that heat is being released by the system to the surroundings. Conversely, if the enthalpy change is positive (ΔH > 0), it means that the reaction or process is endothermic, which implies that heat is being absorbed by the system from the surroundings.

We know that enthalpy change is the;

Bond energy of the reactants - Bond energy of the products

[(-319.2) + (-285.9)] - [(-412.9) + 2(-80.8)]

-604.2 + 573.8

= -30.4 kJ/mol

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The value of deltaHrxn for the conversion of urea into ammonia is given as 30.6 KJ/mol

-319.2 KJ/mol Hof(CO(NH2)2(aq))

-285.9 KJ/mol H0(H2O(l))

-412.9 KJ/mol for Hof(CO2(aq)).

NH3(aq): Hof(NH3(aq)) = -80.8 KJ/mol

A chemical equation that is balanced is:

H2O(l) + CO(NH2)2(aq) = CO2(aq) + 2 NH3 (aq)

H0 rxn is equal to 1*Hof(CO2) + 2*Hof(NH3) - 1*Hof(CO(NH2)2(aq)). -1 Hoof(H2O(l))

ΔH0 rxn = 1*(-412.9) + 2*(-80.8) - 1*(-319.2) - 1* (-285.9)

H0 = 30.6 KJ/mol

Solution: 30.6 KJ/mol

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Answer: Vanadium(III) Sulfide.

Explanation:

Answer:

Animals obtain energy from the food they consume , using that energy to maintain body temperature and perform other metabolic functions. Glucose, found in the food animals eat ,is broken down during the process of cellular respiration into energy source called ATP.

Answer:

Direct-air capture

Explanation:

To understand the technology I'm about to explain, I'll model it to something familiar. As you know, the process of  photosynthesis is where trees and plants use sunlight, water, and carbon dioxide to create energy for themselves, and release oxygen as a byproduct. Direct- air capture is exactly like this. Its pulls in air and then through a range of similiar chemical reactions, it extracts the carbon dioxide from it while returning the rest of the air to the surrounding environment. Except, the Direct-air capture does this at a much faster rate than nature does. The direct-air capture uses a ginormous fan that pulls air in which then passes over plastic surfaces that have potassium hydroxide solutions covered over them. The potassium hydroxide solution chemically binds with the carbon dioxide molecules, removing them from the air and trapping them in the liquid solution as a carbonate salt. The carbon dioxide is then contained where it is compressed and purified and then stored for later use.

Answer:

Radon, Bismuth, Lead, and Thallium

Explanation:

Its from smallest to largest. Hope it helps!

1. The IUPAC name of N is nitrogen.

2. Nitrogen dioxide

3.The IUPAC name of O is oxygen

4.The IUPAC name of OH is hydroxyl.

The IUPAC name of ·0 is a radical. It is commonly found in organic chemistry and plays an important role in many reactions.

IUPAC names for the given compounds are:1.1. N: Nitrogen

The IUPAC name of N is nitrogen.

It is a non-metal and belongs to group 15 in the periodic table. It has an electronic configuration of 1s2 2s2 2p3.1.2. NO2: Nitrogen dioxide

Explanation: NO2 is a chemical compound that is formed by the combination of nitrogen and oxygen. It is a reddish-brown gas that has a pungent odor.

The IUPAC name of NO2 is nitrogen dioxide.1.3. O: Oxygen

Explanation: The IUPAC name of O is oxygen.

It is a non-metal and belongs to group 16 in the periodic table. It has an electronic configuration of 1s2 2s2 2p4.

X: UnknownExplanation: No IUPAC name can be given to an unknown compound as the structure and composition are not known.

Y: Hydroxyl Explanation: The IUPAC name of OH is hydroxyl.

It is a functional group that is composed of an oxygen atom and a hydrogen atom (-OH). It is commonly found in alcohols and phenols. ·0: RadicalExplanation: A radical is a molecule or an ion that contains an unpaired electron.

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Note: The complete question is given below

Provide the IUPAC names for the following compounds:

\(CH_3CH_2CH(CH_3)CH_2CH_2CH_2CH_3\)

C6H5CH(CH3)2

H2NCH2CH2CH2CH2CH2NH2

CH3CH2CH2CH2CH2OH

CH3CH2CH2CHOHCH3

Answer:

Non polar covlant

Explanation:

The concentration of iron used in the titration : 0.009 M

Given

Reaction

Cr₂O₇²⁻ + 6Fe²⁺ + 14H⁺ ⇒ 2Cr³⁺ + 6Fe³⁺ + 7H₂O

0.0093 mol/L potassium  dichromate

200 cm³ of dilute acid, 25cm³   was used in the titration.

Required

the concentration of iron

Solution

Titration formula

C₁V₁n₁=C₂V₂n₂⇒ From equation : n₁=6n₂(1=Cr₂O₇, 2=Fe)

titration average : 33+32.05+32.15+32.1 / 4 = 32.325 cm³(ml)

25 cm³ of iron solution used in titration :

\(\tt V_1=32.325~ml\\\\V_2=25~ml\\\\C_1=0.0093~M\\\\\\\\C_1.V_1.n_2=C_2.V_2.n_1\\\\0.0093\times 32.325\times 6=C_2\times 25\times 1\\\\C_2=0.07215~M\)

Dilution(25 ml from 200 ml iron solution)

\(\tt C_2.V_2=C_1.V_1\\\\0.007215\times 25=C_1\times 200\\\\C_1=0.009~M\)

Answer:

Below

Explanation:

Combination of Calcium(Ca) and Chlorine(Cl); Calcium chloride

\(Ca+Cl_2 -> CaCl_2\)

Combination of Sodium(Na) and Chlorine(Cl); Sodium chloride(salt)

\(Na+Cl_2 -> NaCl\)

Combination of Hydrogen(H) and Oxygen(O);(water)

\(H_2 +O_2-> H_2O\)

Combination of Potassium (K) and Fluorine(f) ; Potassium fluoride

\(K+F ->KF\)

Freezing leads to weathering because water expands when it freezes and cracks rocks open Water expands when it freezes and cracks rocks open

The term weathering has to do with the process of the breakdown of the rocks to give rise to the soil. Now there are are various ways in which the process of weathering could be able to take place. One of the ways that the process of weathering can take place is what we call physical weathering.

In the process of physical weathering, we are looking at some kind of physical pressure which would lead to the breakdown of the rock. This is what makes it different from the chemical and the mechanical forms of weathering.

Thus, the fact that water would expand when we freeze it would mount pressure on the rock and then cause it to weather and form soil.

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Answer:

6.321 × 10^22

Explanation:

Mass of Oxygen =

3.36

g

Molar mass of oxygen (

O

2

) = 16 x 2 =

32

g

m

o

l

−

Total molecules in oxygen = Mass in grams/Molar mass x

N

A

=

3.36

32

x

6.02

x

10

23

=

6.321

x

10

22

Note:

N

A

(Avagadro's number) =

6.02

x

10

23

Hope it helps...

Evaporation causes the dew to vanish when the temperature of the atmosphere rises with the rising of the sun.

A kind of vaporization called evaporation takes place on the surface of a liquid as it transitions into the gas phase. When humidity impacts the rate of evaporation of water, for example, a high concentration of the evaporating material in the surrounding gas considerably slows down evaporation.

Similar to how perspiration evaporates from your body on a hot day to cool you down, dew evaporates as it cools the plant. This lessens heat exhaustion in extremely hot settings. Some species, particularly desert plants, are capable of directly absorbing water via their leaves.

Thus, Evaporation causes the dew to vanish when the temperature of the atmosphere rises with the rising of the sun.

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Types of luminous flames:

1. Yellow Luminous Flame

2. Smoky Luminous Flame

3. Orange Luminous Flame

4. Blue Luminous Flame

Luminous flames are characterized by their visible glow, which is caused by the incomplete combustion of fuel. The presence of soot particles in the flame causes the emission of light. There are different types of luminous flames, which can be classified based on their fuel composition and burning conditions. Here are some common types of luminous flames:

1. Yellow Luminous Flame: This is the most common type of luminous flame, often seen in open fires, candles, and gas stoves. It appears yellow due to the presence of soot particles in the flame. Yellow flames indicate incomplete combustion of hydrocarbon fuels, such as methane, propane, or natural gas. The high carbon content in these fuels leads to the formation of soot, which emits visible light.

2. Smoky Luminous Flame: This type of flame is characterized by a significant amount of black smoke and soot production. It is commonly observed in poorly adjusted or malfunctioning burners or engines. The excessive presence of unburned fuel in the flame results in incomplete combustion and the emission of dark smoke particles.

3. Orange Luminous Flame: An orange flame indicates a higher combustion temperature compared to a yellow flame. It is often seen in more efficient burners or when burning fuels with a higher carbon content, such as oil or diesel. The higher temperature helps in burning more of the carbon particles, reducing the amount of soot and making the flame appear less yellow.

4. Blue Luminous Flame: A blue flame is typically associated with complete combustion. It indicates efficient burning of fuel, resulting in minimal soot formation. Blue flames are commonly observed in gas burners or Bunsen burners. The blue color is a result of the combustion of gases, such as methane, in the presence of sufficient oxygen.

It's important to note that the luminosity of a flame can vary depending on factors such as fuel-air mixture, combustion temperature, and the presence of impurities. Achieving complete combustion and minimizing the production of soot is desirable for efficient and cleaner burning processes.

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Yes, the AgCl will precipitate out from this solution.

First of all we know that[Ag^+] = [Cl^-] = [AgCl]

As such we have that

[AgCl] = √Ksp

= √1.6 x 10^-10

= 1.26 8 10^-5 M

Number of moles of the AgCl = 1.26 8 10^-5 M * 13.6/1000

= 1.6 * 10^-7 moles

Then;

Number of moles of NaCl = 13.6/1000 * 0.0246

= 3.3 * 10^-4 moles

Number of moles of AgNO3 = 0.00482 g /170 g/mol

= 2.8 * 10^-5 moles

The reaction equation is;

AgNO3 + NaCl --->AgCl + NaNO3

The reaction is 1:1 thus AgNO3 is the limiting reactant and the amount of the AgCl formed is  2.8 * 10^-5 moles.

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Answer:

A) Trypsin has an optimal pH of 8.

B) Pepsin works best at a pH of 3.

D) Pepsin works best in more acidic conditions.

The statements that accurately describe the action of trypsin and pepsin are as follows:

Thus, the correct options for this question are A, B, and D.

Enzymes may be defined as the types of biocatalysts that significantly increase the rate of chemical reactions without being consumed in the overall process. It is thought that all cellular processes and reactions are mediated by enzymes.

Both trypsin and pepsin are the classes of enzymes that effectively catalyze the breakdown of proteins in food into smaller peptide chains or into individual amino acids.

But the mode of action for both enzymes may differ a lot. For example, trypsin work best at a slightly basic condition of pH 8 while pepsin works best in an acidic environment.

Therefore, the correct options for this question are A, B, and D.

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