What is the half-life of a radioisotope if a 50-g sample becomes 25 g after 18
days?
O A. 25 days
O B. 9 days
O C. 50 days
O D. 18 days

Answers

Answer 1

Answer:

18 DAYS IS THE HALF LIFE OF THE RADIOISOTOPE.

Explanation:

Using the formula

Nt = No * (1/2)^t/t1/2

where;

Nt = amount remaining = 25 g

No = Initial amounrt of the radioisotope = 50 g

t = time elapsed = 18 days

t1/2 = half life = unknown

Substitute the values into the equation and obtain the half life of the radioisotope;

Nt = No * (1/2) ^t/t1/2

25 = 50 * (1/2) ^18/t1/2

25 /50 =  (1/2)^18/ t1/2

1/2 = (1/2)^18/t1/2

1/2)^1 = (1/2)^18/t1/2

1 = 18/t1/2

t1/2 = 18 days.

So therefore the half life of the radioisotope is 18 days.

Answer 2

Answer:

18 days

Explanation:

Did it on A pex


Related Questions

Which of the following statements describes electromagnetism?

Answers

Answer:

c)Magnetism can cause electrons to flow, and electricity can make a wire magnetic.

Explanation:

If this is your question:

Which of the following statements describes electromagnetism?

a)Magnetism and electricity are both used by society to do work.

b)Magnetism and electricity both include protons and electrons.

c)Magnetism can cause electrons to flow, and electricity can make a wire magnetic.

d)Electrons are attracted to the protons in magnets.

Answer:

magnetism can cause electrons to flow, and electricity can make a wire magnetic

Explanation:

a p e x :)

Which phrase best describes the path of a light wave ?

A. Straight away from the source
B. Spiraling around the source
C. Perpendicular to the source
D. Parallel to the source

Answers

Answer:

La B

Explanation:

It's B on Ap3x

Straight away from the source

Select True or False: Nitric acid is formed by the gas-phase hydrolysis of N2O5. The energy profile curve for the reaction N2O5 H2O → 2HNO3 is shown here. The reaction is endothermic and the activation energy of the reverse reaction is larger than for the forward reaction.

Answers

Answer:

True

Explanation:

Because Nitric acid is formed by the gas-phase hydrolysis of N2O5. The energy profile curve for the reaction N2O5 H2O → 2HNO3 is shown here. The reaction is endothermic and the activation energy of the reverse reaction is larger than for the forward reaction.

Consider the equations below.
H₂ → 2H
CHA+HC2H5
C2H5 + HC2H6
When these equations are added together, what will the overall equation be?
C₂H4+H₂C₂H
H2 + CH4 + 2H + C2H5+ → 2H + CH3 + CHE
C2H4 +C2H4 + H2>C2H5 + C2H5​

Answers

Answer:

a

Explanation:

The overall equation is [tex]C_2H_4 + H_2 ---- > C_2H_6[/tex].

What is Chemical Equation?

A chemical equation is defined as a symbolic representation of a chemical reaction in the form of symbols and formulas, in which reactant elements are given on the left and product units on the right.

For example,

[tex]NaOH+ HCl ---- > NaCl+ H_2O[/tex]

In this, reactants are converted to products which is symbolized by a chemical equation. For example, iron (Fe) and sulfur (S) combine to form iron sulfide (FeS).

Fe(s) + S(s) → FeS(s)

here, the plus sign indicates that iron reacts with sulfur.

Thus, the overall equation is [tex]C_2H_4 + H_2 ---- > C_2H_6[/tex].

Learn more about Chemical Equation, here:

https://brainly.com/question/30087623?

#SPJ2

Which compound contains both sigma and pi bonds

Answers

Any compound with multiple covalent bonds
The difference starts with sigma bonds. Electrons are disabled by nuclear attraction from both bonding nuclei, while within pi bonds, electrons are loosely held in the general proximity of either bonding nucleus. All pi bonds are naturally delocalisable. People are most commonly used to call it “double bond character,” but since it can occur for triple bonds as well as bonding that never even fully constitutes a double bond, stigma character and pi character are more appropriate, in my opinion.

Use the drop-down menus to complete the statements

Answers

Answer:

First one: group

Second one: period

Third one: number of valence electrons

Last one: increases

What is a criterion for all products made using the process of technological design? The product must be cheaper than similar products.

The product must be available to any user who wants it.

The product must solve the problem for which it was designed.

The product must be capable of solving a variety of problems.

Answers

Answer:

C. The product must solve the problem for which it was designed.

Explanation:

Technological design is the study, development and application of technological process with the intent of designing a product to solve required problem.The process could be based on the use of a computer.

Generally, technological process and development always tend to design a problem solver product. Through this process, more new technologies are produced.

Therefore in technological process, the product must solve the problem for which it was designed.

Answer:

C) The product must solve the problem for which it was designed.

2. Which change in oxidation number indicates
oxidation?
A) -1 to +2
C) -1 to - 2
B) +3 to +2
D) +2 to -3

Answers

Answer:

A)

Explanation:

Increasing of oxidation number shows that the process is oxidation(or losing of electrons).

-1 to +2, oxidation number is increased. This is an oxidation process.

-  

1.)A strong acid solution requires 3.2 grams of sulfuric acid (H2SO4). How many molecules of sulfuric acid are in the solution?

2.) While measuring out the sulfuric acid you accidentally spilled some of it! Before trying to clean it up you put some baking soda (NaHCO3) on to it neutralize it. If you scatter 7.8 g of baking soda on the acid how many moles of baking soda have you used?

Answers

Answer: 1. There are [tex]0.20\times 10^{23}[/tex] molecules of sulfuric acid  in the solution.

2.  0.093 moles of baking soda have been used.

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

To calculate the moles, we use the equation:

1. [tex]\text{Number of moles of sulpfuric acid}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{3.2g}{98g/mol}=0.033moles[/tex]

1 mole of [tex]H_2SO_4[/tex] contains = [tex]6.023\times 10^{23}[/tex] molecules of sulfuric acid

Thus mole of [tex]H_2SO_4[/tex] contains = [tex]\frac{6.023\times 10^{23}}{1}\times 0.033=0.20\times 10^{23}[/tex] molecules of sulfuric acid

There are [tex]0.20\times 10^{23}[/tex] molecules of sulfuric acid  in the solution.

2.  [tex]\text{Number of moles of baking soda}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{7.8g}{84g/mol}=0.093moles[/tex]

0.093 moles of baking soda have been used.

PLEASE HELP!!!

Design criteria are the desired features of a design. Identify at least two criteria for the design of the ammonia-making process. Explain why these criteria are important.

Answers

Answer:

Two design criteria for the design of the ammonia making process are;

1) Sustainable hydrogen production by renewable energy

2)  Sustainable use of the ammonia-water thermal absorption cycle to retrieve the ammonia present in the waster water

Explanation:

Ammonia is produced from natural gas in the following process;

H₂ + RSH → RH + H₂S

H₂S + ZnO → ZnS + H₂O (Waste water)

CH₄ + H₂O → CO + 3H₂

CO + H₂O → CO₂ + H₂

Ammonia is then produced by reacting the produced hydrogen with nitrogen in the presence of a catalyst in a process known as the Haber-Bosch process as follows;

3H₂ + N₂ → 2NH₃

The

The design criteria for the design of the ammonia making process therefore as follows;

1) Sustainable use of renewable energy to produce hydrogen gas from the electrolysis of water

2)  Use of the ammonia-water thermal absorption cycle to retrieve the ammonia present in the waster water.

The branch of science which deals with chemicals and their bond is called chemistry.

The two ways by which we can design ammonia making process is as follows:-

Two design criteria for the design of the ammonia making process are:-

Sustainable hydrogen production by renewable energy .The conversion of urea for the production of ammonia.

The usage of ammonia is important in these ways:-

They act as a fertilizer which helps to boost the growth of plants.They act as a poison to humans and many animals, so we have to extract it and handle it with care.Ammonia is also used as an inflammable gas.

Hence, these are the design for the ammonia-making process.

For more information, refer to the link:-

https://brainly.com/question/19524691


is the study of the natural world through observation and experimentation.

Answers

Answer:

YES

Explanation:

The systematic study of the structure and behavior of the physical and natural world through observation and experiment.

When an F atom becomes an F-ion, the Fatom
gains a proton
gains an electron
loses an electron
loses a proton

Answers

When an F atom becomes an F-ion, the F atom gains an electron.

An atom is the smallest indivisible particle of an element. An atom consists of proton, electron and neutron, which are called subatomic particles.

An atom becomes charged when it loses or gains an electron. The charged atom is called an ion.

An atom loses electrons to become positively charged i.e. a cation while it gains electrons to become negatively charged i.e. an anion.

Therefore, when an F atom becomes an F-ion, this means that the F atom gains an electron.

Learn more at: https://brainly.com/question/13495616?referrer=searchResults

The Fluoride ion given has a -ve charge onto it. Thus in order to become stable Fluorine gains an electron. Thus option b is correct.

The elements in the periodic table try to attain the stable noble gas configuration in the order to become stable. The noble gas configuration has the elements to be less reactive.

When the atom loses an electron in order to become more stable,  a +ve charge has been implemented onto the ion.

When the atom gains an electron to become stable, a -ve charge has been added to the ion.

The Fluoride ion given has a -ve charge onto it. Thus in order to become stable Fluorine gains an electron. Thus option b is correct.

For more information about atom, refer to the link:

https://brainly.com/question/21850455

What does the period number tell about the energy levels occupied by electrons in an atom?

Answers

The period number tells which is the highest energy level occupied by the electrons

Answer:

Number of energy levels that the element has.

Explanation:

The period number (n) is the outer energy level that is occupied by electrons. The period number that an element is in, is the number of energy levels that the element has.

The disinfectant hydrogen peroxide (H2O2)
decomposes to form water and oxygen gas.
How much O2 will result from the decomposition of 2.22 mol of hydrogen peroxide?

Answers

Answer:

1.1 mol of O2

Explanation:

First we need the balance chemical equation which is

2 H2O2 -------> 2 H2O + O2

This is important because in stoichiometry you can go from units of one thing to other by using mole ratios, here the mole ratio is 2 mol of H2O2  for one mole of O2.

[tex]2.2 mol H2O2 \frac{1mol O2}{2 mol H2O2}[/tex] = 1.1 mol of O2

formation of magnesium chloride​

Answers

-Pure magnesium is commonly made by separating it from seawater. This process is known as electrolysis. The liquid magnesium formed is cooled into convenient blocks of metal known as ingots. The chlorine gas is recycled to form hydrochloric acid for the production of more magnesium chloride.

Why does diamond not conduct electricity

Answers

Answer: no free electrons

Explanation: Diamond is very hard due to the strong covalent bonds and rigid tetrahedral 3d arrangement. It does not conduct electricity, as there are no electrons free to move and carry charge through the structure.

It does not conduct electricity, as there are no electrons free to move and carry charge

According to solubility rules, which of the following compounds is soluble in water?
A. Na Coz
B. BaSO4
O C. Ca(NO3)2
D. K3PO4​

Answers

Answer:

Na2CO3

Explanation:

Na2CO3 is a compound soluble in water. So the correct option is A.

What are solubility rules?

The common ionic solids' solubility laws are as follows. When two rules seem to conflict with one another, the prior rule is used.

Group I element salts (Li+, Na+, K+, Cs+, and Rb+) are soluble. The few exceptions to this rule are rare. Ammonium ion (NH4+) salts are also soluble in water.Nitrate ion (NO3-) salts are often soluble.In general, salts containing Cl, Br, or I are soluble. Ag+, Pb2+, and (Hg2)2+ halide salts are significant exceptions to this norm. PbBr2, Hg2Cl2, and AgCl are hence insoluble.Silver salts are often insoluble. Most silver salts are insoluble, with the exception of AgNO3 and Ag(C2H3O2).Sulfate salts are often soluble. This rule has some notable exceptions, such as CaSO4, BaSO4, PbSO4, Ag2SO4, and SrSO4.The majority of hydroxide salts are hardly soluble. Group I element hydrate salts are soluble. Group II elements (Ca, Sr, and Ba) have soluble hydrate salts. Transition metal and Al3+ hydrate salts are insoluble. Fe(OH), Al(OH), and Co(OH)2 are so insoluble.The majority of transition metal sulfides, such as CdS, FeS, ZnS, and Ag2S, are very insoluble. Sulfides of lead, antimony, bismuth, and arsenic are also insoluble.Many times, carbonates are insoluble. Group II carbonates, including CaCO3, SrCO3, and BaCO3, as well as FeCO3 and PbCO3, are insoluble.Most of the time, chromates are insoluble. PbCrO4 and BaCrO4 are examples.Many phosphates, like Ca3(PO4)2 and Ag3PO4, are insoluble.Many fluorides, including BaF2, MgF2, and PbF2, are insoluble.

Therefore, the correct option is A

Read more about solubility, here

https://brainly.com/question/8591226

#SPJ2

What systems need to be in place to ensure fairness in healthcare?

Answers

Answer:

The Healthcare system should be a welcome place to the different tiers of people in the society. There should be zero form of discriminations and everyone should be should be treated in the same way. Defaulters should be frowned at and adequate punishments should be meted out. There should be strict accountability of the funds made available to the healthcare centers to prevent diversion and any corrupt practices. These systems need to be in place to ensure fairness in healthcare.

What evidence did the team examine that matter is conserved when dry ice changes into a gas?

Answers

Answer:

Im not sure what you mean but I hope what I wrote helps you!

The Law of Conservation of Matter says that the amount of matter stays the same, even when matter changes form. Sometimes it may seem that matter disappears during a science experiment, but this law tells us that matter cannot magically appear or disappear, it simply changes from one form to another.

Explanation:

how much volume do the gas molecules take up in an inflated balloon

Answers

Answer:

The volume of a gas is determined by the volume of the container it is in. Gases take the shape of their container and the volume of the container....

Explanation:

What happens to the volume or size of a balloon as it rises in the air?

When a balloon goes up higher in the air, its size will increase. Since there's less air in the upper atmosphere, there's less stuff pushing back on the balloon, and hence the pressure is lower, which allows the balloon to expand.

Is pressure inside a balloon greater?

The pressure inside the balloon is higher than the pressure on the outside. ... And the direction of airflow is always from higher to lower pressure. If the pressure was same then there would be no airflow and if the pressure outside was higher , air will flow from outside to the inside of the balloon.

What is the relationship between volume and pressure?

Boyle's law is a gas law, stating that the pressure and volume of a gas have an inverse relationship. If volume increases, then pressure decreases and vice versa, when temperature is held constant. Therefore, when the volume is halved, the pressure is doubled; and if the volume is doubled, the pressure is halved.

Mark as brainliest if liked it. Thanks hope this helps

It depends on how many volume the container is in

How many grams of chlorine gas are needed to react with 3.5 liters of a 1.7 molar
potassium bromide solution?
Cl2 + 2 KBr - 2 KCl + Br2

Answers

Answer: 211.2 grams

Explanation:

To calculate the number of moles for given molarity, we use the equation:

[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution in L)}}[/tex]     .....(1)

Molarity of [tex]KBr[/tex] solution = 1.7 M

Volume of solution = 3.5 L

Putting values in equation 1, we get:

[tex]1.7M=\frac{\text{Moles of}KBr}{3.5L}\\\\\text{Moles of }KBr=\{1.7mol/L\times 3.5L}=5.95moles[/tex]

The balanced chemical reaction is:

[tex]Cl_2+2KBr\rightarrow 2KCl+Br_2[/tex]

According to stoichiometry:

2 mole of KBr requires = 1 mole of [tex]Cl_2[/tex]

5.95 moles of KBr requires = [tex]\frac{1}{2}\times 5.95=2.975[/tex] moles of [tex]Cl_2[/tex]

Mass of [tex]Cl_2=moles\times {\text {Molar mass}}=2.975mol\times 71g/mol=211.2g[/tex]

Thus 211.2 grams of chlorine gas are needed to react with 3.5 liters of a 1.7 molar potassium bromide solution

rainwater is slightly acidic.why?

Answers

Answer:

Rainwater is slightly acidic because...Water reacts with carbon dioxide to form carbonic acid. Due to high carbon dioxide emission in oceans, it explains why sea waters are acidic. Carbonic acid then breaks down into hydrogen ions and hydro carbonates ions. The hydrogen ion raises the water pH and, thus, causes the rainwater to be slightly acidic.

Answer:

Explanation:

rainfall is slightly acidic because of the presence of dissolved carbonic acid. ... The gases of sulfur oxides and nitrogen oxides are chemically converted into sulfuric and nitric acids.


56. What would be the valence electrons of 14Si, 16S, 32Ge respectively?
A. 4, 2,2
B. 4, 6,8
C. 4, 6,6
D. 4,6,4​

Answers

Answer: D. 4,6,4

Explanation:

The valence electron is the electron found in the outermost shell of an atom, and participates in bond formation.

For the following element, the valence electron can be noticed when we write the electronic configuration of each element.

Silicon =  1s2 2s2 2P6 3s2 3p2

Sulphur = 1s2 2s2 2P6 3s2 3p4

Germanium =  1s2 2s2 2P6 3s2 3p6 3d10 4s2 4p2


What is the function of these organelles?

endoplasmic reticulum:

Golgi body:

mitochondrion:

ribosome

Answers

Answer:

endoplasmic reticulum:

✔ helps in the production and movement of materials

Golgi body:

✔ packages and distributes materials in and out of cell

mitochondrion:

✔ supplies energy that the cell uses

ribosome:

✔ produces proteins for the cell

Explanation:

I did it on Edge

The function of endoplasmic reticulum is it helps in production and movement of a material.

What is endoplasmic reticulum?

Endoplasmic reticulum is defined as a network of membranous tubules present within the cytoplasm of a eukaryotic cell.

It is one of the important organ of human body system which helps us in production and movement of material from one body part to another.  

Golgi body helps in packaging and distribution of material in and out of cells.

Mitochondrion supply the energy to the cell. It is called as a power house of cell.

Ribosome helps to produce protein for the cell. It is called as protein factory.

Thus, the function of endoplasmic reticulum is it helps in production and movement of a material.

To learn more about endoplasmic reticulum, refer to the link below:

https://brainly.com/question/1311891

#SPJ2

If the pH of a solution is 6.2, what would the pOH be?
O A. 7.8
B. 8.9
C. 12.4
D. 5.8
SUBMIT

Answers

Answer:

7.8

Explanation:

pH + pOH = 14

pOH = 14 - 6.2

= 7.8

Which organic compound is saturated?

1.ethene
2.propene
3.ethyne
4.propane

Answers

Answer:

3. ethyne

Explanation:

Highest ratio of hydrogen to carbon? I'm not sure I found it on the internet but the answer is right

the particles with a negative charge are


1) protons
2)neutrons
3)electrons

Answers

Answer:

the particles with a negative charge are protons

I am sure it is electrons.

How are the particles in solid ice similar to the particles in liquid water, and water vapor? How are they different?

Answers

Matter are anything that is made up of atoms. The similarity among  solid ice, liquid water and water vapor is the water molecule and dissimilarities  is the difference in kinetic energy.

What is matter?

Matter is a substance that has some mass and can occupy some volume. The matter is mainly used in science. Matter can be solid, liquid or gas.

The similarity in the in the particles of  solid ice, liquid water and water vapor is that each of these have same type of molecules that is water molecules. The dissimilarities in  the in the particles of  solid ice, liquid water and water vapor is that particles of of each of these have different kinetic energy.

Therefore, similarity among  solid ice, liquid water and water vapor is the water molecule and disimilarity is the difference in kinetic eneergy.

To learn more about matter, here:

https://brainly.com/question/4562319

#SPJ1

If two identical atoms are bonded together, what kind of molecule is formed?
A. A bent, nonpolar molecule
B. A linear, polar molecule
C. A linear, nonpolar molecule
D. A linear, ionic molecule

Answers

Answer:

C. A linear, nonpolar molecule

Explanation:

Molecules which are alike usually have the same degree of pull which results in them sharing electrons. This sharing of electrons is known as the molecules exhibiting Covalent bonding between them.

The equal pull also results in the cancelling out of electrons and favoring non polar bonds due to the absence of free electrons which would have been able to interact with H2O in a polar binding system.

Answer:

C

Explanation:

APEX

What is the mass number of an atom that contains 19 protons, 19 electrons, and 20 neutrons?

Answers

Answer:

39

Explanation:

Total protons + total neutrons = mass number

Other Questions
1. Why did Christopher Columbus wantto find new trade routes? Consider the following quadratic equation: 25x2=36 Using the standard form ax2+bx+c=0 of the given quadratic equation, factor the left hand side of the equation into two linear factors. Need help ?? Anyone? Two positive, consecutive, odd integers have a product of 143.Complete the equation to represent finding x, the greater integer.x(x ) = 143What is the greater integer? Which early European settlement is marked by the star on the map? Read the quotation by Ralph Waldo Emerson. Which of Adam Smiths ideals are reflected in the quotation from Emerson? Greater competition will benefit the consumer. Private ownership is the basis for success. Government should not play a role in the free market. Only industrious people should have access to capital. Butterflies and moths depend upon _________.A forestsB blossomsC seedsD lakes What is the tangent ratio for A? please help me !!slope and y-intercept*image attached How many moles are in 255 mL of a 2.35 M solution of H2SO4? (6m^5+3-m^3-4m)-(-m^5+2m^3-4m+6)= Which substances are products of a fermentation reaction?1.water and carbon dioxide2.alcohol and carbon dioxide3.soap and glycerol4.ester and water Find the area of the figure Corey and David both have lots of video games. The number of games Corey has can be represented by x . Ricky has 3 times as many games as Corey. The total number of games is 64 . What is x, the total number of games Corey has? Short hair (S) is dominant to long hair (s) in cats. What would be the genotype(s) of a cat with long hair A SS or SsB ssC SsD SS Whats the vertex y=-1/2(x+3)^2-1 Which is an example of a nonverbal communication?interrupting the conversation to give your opinionnodding your head to show agreementusing a standard greeting such as helloasking questions for clarification Find the vertex, focus, directrix, and focal width of the parabola.x = 4y2 There are two different alleles for flower color, P and p. The image shows a purple sweet pea that is labeled with its two alleles for petal color. A purple sweet pea is labeled Upper P Upper P. Which is the genotype of the sweet pea? Give two causes of MalnutritionHELP :)