5. Selenium-83 has a half-life of 25.0 minutes. How many minutes would it take for a 10.0
mg sample to decay and have only 1.25 mg of it remain?

Answers

Answer 1

Explanation:

10.0mg / 1.25mg = 8

1/8 of the original mass => 3 half-life phases

Hence it will take 25.0 min * 3 = 75.0min.


Related Questions

What should a student do to set a goal? Check all that apply.

Create a plan.
Make a schedule.
Schedule lots of tasks.
Rush into the goal.
Pace him or herself.

Answers

Answer:

create a plan

the ways of of a student to set a goal

1. Write clear and measurable goals

2.Create a specific plan for each goal

3.Read your goals daily and visualize yourself accomplishing them

4. Reflect yourself to see if you are on target

5. Revise your action plans if needed.

1.)make a plan

2.)make a schedule

5.)pace him or herself

How can you identify a redox reaction?
O A. The number of protons has changed in an atom.
O B. Electrons have transferred from one atom to another.
O C. The charges on each side of the equation cancel.
O D. Metal atoms have rearranged in the compounds.
SUBMIT
PREVIOUS

Answers

Answer: The Correct Answer is Choice B.

Explanation: I just took the quiz.

ANSWER:

B. Electrons have transferred from one atom to another.

EXPLANATION:

An oxidation-reduction (redox) reaction is a reaction which involves the change in oxidation number of the atoms involved. Since the oxidation number changes, this means that one atom has to lose electrons and another has to accept electrons. The reactant that loses electrons is called REDUCING AGENT while the reactant that gains electrons is called OXIDIZING AGENT.

For example, in a reaction between iron and oxygen as follows:

4Fe+ 3O2→2Fe2O3

Iron is reduced from +2 to 0 because it accepts electrons from oxygen while oxygen is oxidized from -2 to 0 because it transfers electrons to iron.

Hence, a redox reaction can be identified by the transfer of electrons from one atom to another.

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What gases make up Jupiter? Name moons of Jupiter Can Jupiter sustain life How many rings does Jupiter have The weather on Jupiter​

Answers

Answer: Jupiter is made up predominantly of hydrogen. Jupiter's Moon, Europa, might be able to support life. Jupiter has 3 skinny rings. Usually around -234 degrees Fahrenheit.

Ti(SO4)2 chemical compound?

Answers

Answer:

Titanium(IV) Sulfide

Explanation:

Titanium (iv) sulfide

What one word completes the
If a plant is losing water faster than it can be replaced by its roots, its stomata will
sentence?

Answers

Answer:

it causes the cells to become flaccid and the stomata openings to close

Explanation:

the stomata closes to reduce water loss

When a plant is losing water at a greater rate than it can be replaced by its roots, then in such a case, the stomata will get close to reduce the loss of water.  

• Generally, the opening of stomata takes place in the day and gets close at night. To prevent the loss of water stomata get close during the night.  

• However, in certain cases, even during the day, when the plant experiences loss of water due to conditions like drought then stomata remain close during the day also.  

• This opening and closing of stomata take place as a response to the signals from the external environment.

Therefore, when more amount of water is loosing from the plant than getting absorbed by the roots, the stomata gets the signal to remain close to prevent water loss and death of the plant.

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How does a magnet separate mixtures like sand and iron filings?​

Answers

Answer:

because iron is magnetic and sand is not

Explanation:

because iron filings are magnetic, but sand is not, so the magnet separates the filings from the sand due to magnetic attraction

Suppose a lab procedure calls for 0.75 L of a 0.25 M CaCl2 solution. How much of a 10.0 M stock solution do we dilute?

Where the diluted solution is #2 (the numerator)

Answers

Answer:

V₁ = 0.019 L

Explanation:

Given data:

Molarity of stock solution = 10.0 M

Volume of stock solution = ?

Molarity of CaCl₂ = 0.25 M

Volume of CaCl₂ = 0.75 L

Solution:

Formula:

V₁ = M₂V₂ / M₁

V₁ = 0.25 M × 0.75 L / 10.0 M

V₁ = 0.1875 M.L / 10.0 M

V₁ = 0.019 L

Decide which element probably forms a compound with hydrogen that has a chemical formula most and least similar to the chemical formula of the compound formed by hydrogen and sulfur.

Answers

Answer:

Most similar- oxygen

Least similar- sodium

Explanation:

The complete question is shown in the image attached.

Now let us consider all the options in the questions carefully. We do know that hydrogen forms  covalent bonds with sulphur. Two hydrogen atoms form form two polar covalent bonds with one sulphur atom. The molecule is bent owing to the presence of two lone pairs of electrons on the sulphur central atom.

Oxygen is in the same group as sulphur in the periodic table. The compound between hydrogen and sulphur is strikingly similar to the compound formed between sulphur and hydrogen due to chemical similarity of compounds of elements in the same group of the periodic table. Hence H2O bears the greatest similarity to H2S.

The bond between hydrogen and halogens is also polar covalent but less similar to the bond between sulphur and hydrogen.

Lastly, the bond between hydrogen and sodium is ionic and least similar to the bond between hydrogen and sulpur. We actually have in that compound, Na^+ H^-. Sodium transfers one electron to hydrogen as is implied in the ionic formula shown.

Hence the answer above.

Question 9 of 10
What is stoichiometry used for?
A. Calculating the mass of a product from the number of moles of
B. Calculating the molarity of the limiting reagent used in a reaction
DC. Calculating the actual yield of a product in a chemical reaction
D. Calculating the weighted average atomic mass of an element
reactants

Answers

Stoichiometry is used for calculating the mass of a product from the number of moles of reactants. The correct option is A.

What is stoichiometry?

Stoichiometry is made up of two words, stoikhein, which means element, and metron, which means measure. Stoichiometry is a method of determining the data by using the knowledge of reactants and products.

There are five steps of stoichiometry that are the following:

Obtain all measurement information from the task.Change all measuring units to the same base units.Compose a thoughtful response.Ascertain the species' stoichiometry.Calculate the appropriate quantity in step five.

Thus, the correct option is A. Calculating the mass of a product from the number of moles of reactant.

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Would you expect oxygen (O) to react more like sulfur (S) or nitrogen (N)? Support your prediction with evidence .

Answers

Answer:

Sulfur

Explanation:

Oxygen like sulfur would chemical react and combine with other compounds in the same way. This is because they are both located in the same group on the periodic table.

Elements in the same group have the same chemical properties and they will react the same way.

The general formula of the elements in this group are ns² np⁴.

All the elements in this group have 4 electrons in their np⁴ shell and they belong to the p-block.

Which lists important roles of coral reefs?
cleaning oil from oceans, protecting beaches, producing oxygen
producing oxygen, offering medical benefits to humans, supporting a variety of organisms
supporting a variety of organisms, cleaning oil from oceans, producing oxygen
offering medical benefits to humans, protecting beaches, supporting a variety of organisms

Answers

I believe the answer is C which is supporting a variety of organisms, cleaning oil from oceans, producing oxygen.

Answer:

D. offering medical benefits to humans, protecting beaches, supporting a variety of organisms

Explanation:

I took the test and put C and got it wrong and l went back to see what the correct answer as and it was D.

2
A sample of water has a volume of two liters and is shaped like a cylinder in one container. In a much larger container, the water
still has a volume of two liters, but it is shaped like a rectangle
What state of matter is the water in?
OA. Solid
OB. magnetic
OC. plasma
OD. liquid
Reset
Submit

Answers

Answer:

D. liquid

Explanation:

Matter, which is any substance that has weight and occupies space, can exists in three states namely: solid, liquid and gaseous. In this question, water is being described as matter.

According to this question, a sample of water of volume 2litres is shaped like a cylinder in one container and shaped like a rectangle in another larger container. Based on this observation, the water sample is in a LIQUID STATE because a liquid has no indefinite shape but takes the shape of its container.

Hence, this water sample, takes the shape of its cylindrical container in the first scenario and shape of its rectangular container in the second scenario.


Write ashort note on the
first battle of
of panipat​

Answers

Answer:

The First Battle of Panipat was fought between the invading forces of Babur and the Lodi Empire, which took place on 21 April 1526 in North India. It marked the beginning of the Mughal Empire. This was one of the earliest battles involving gunpowderfirearms and field artillery.

For you to write an essay on  Panipat first bring into view

Introduction body conclusion

Then write a brief story using this format.

How to write a short note on the first battle of Panipat?

In writing this essay, you must consider the structure and content of the essay or short note

For structure kick off with

Introduction body conclusion

In conclusion, for the content of the short note you can consider this,

Panipat fought its first battle on 21 April 1526 in the North of India, This battle was fought between the invading powers of Babur and the Lodi Empire.

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Give the IUPAC name for each compound.

Answers

Answer:

a. 1-fluoro-3,3,4-trimethyl-pentane.

b. 1-iodo-3-ethyl-2-methyl-hexane.

c. 1,3-dichloro-5-dimethyl-hexane.

d. 1-bromo-3-methyl-cyclopentane.

Explanation:

Hello!

In this case, according to the IUPAC rules for the listed alkyl halides, we first need to name the halogens (considering periodic order) then alkyl radicals and finally the parent chain; thus, the names are given below:

a. 1-fluoro-3,3,4-trimethyl-pentane.

b. 1-iodo-3-ethyl-2-methyl-hexane.

c. 1,3-dichloro-5-dimethyl-hexane.

d. 1-bromo-3-methyl-cyclopentane.

e. 5-chloro-1-bromo-1,1,5-trimethyl-pentane (radicals are not clear).

Best regards!

Ppredict the identity of the precipitate in the below reaction:

BaCl2(aq) + K2SO4(aq) →

Answers

Answer:  The precipitate formed is [tex]BaSO_4[/tex]

Explanation:

A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid or precipitated form are represented by (s) after their chemical formulas.  

A double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.  

The balanced chemical equation is:

[tex]K_2SO_4(aq)+BaCl_2(aq)\rightarrow BaSO_4(s)+2KCl(aq)[/tex]

HELP me plzzzzzzzzzzzzzzzzz

Answers

Answer:

Explanation:

bblblblbllbllbllb1234w

Tell me this why don't water stop my mouth from burning but milk or malk does this s for 32 points

Answers

Answer:

water spreads the spicy taste around your mouth, while milk does not and it helps the hot taste go away.

Explanation:

Answer:

water makes ur mouth burn more but milk it helps bc of what's in it

What is one way in which sound and light are alike? PLEASE HELP IF YOU WANT BRAINLEIST AND TO HAVE YOUR COMMENT LIKED!!

A. They both travel easily through wood.
B. They are both types of energy.
C. both can travel through outer space.
D. They both make it easier for you to see what you are doing.

Answers

B. They are both types of energy

Answer:

They are both types of energy.

Explanation:

The last 2 are true for light, and the first one is true for sound.

Hope this is right, sorry if it is not.

What is the definition of climate?
1) An area's long term weather pattern
2)When large air masses of different density, moisture, and temperature mee
3)The state of the atmosphere at a given place and time
4)Large volume of air that has similar characteristics of temperature and water
vapor content

Answers

Answer:

1) An area's long term weather pattern

Explanation:

Climate is defined as the weather pattern in an area for the long term. Climate means the usual condition of the humidity, temperature, wind, rainfall, and atmospheric pressure in the surface area of Earth for the long term. Usually the time period for a climate in a region is taken over 30-years.

Weather is the state of the atmosphere and climate the long-term weather pattern of the area. For example: degree to which it is hot or cold is weather and expect snow in the Northeast in every January is climate.

Hence, the correct answer is "1) An area's long term weather pattern".

Using the two cell reduction potentials shown for their corresponding reaction, calculate the cell potential for a voltaic cell made from these two systems.

Question 17 options:


A)


1.68 V


B)


–0.78 V


C)


0.78 V


D)


–1.68 V

Answers

Answer:

Theory- 1 to 7

Explanation:

Exercise- 8 to 25

ect

The right alternative is Option D (0.78 V).

According to the question,

By putting the values, we get

Cu+2 + 2e → Cu E = 0.52 V

Ag+1 + 1e Ag E° = 0.78 V

= 1.23 - 0.45

= 0.78.

Is cell potential negative or positive?

negative

The standard cell potential is quite negative, so the reaction will not occur spontaneously as written.

Missing parts of the question.

Using the two cell reduction potentials shown for their corresponding reaction, calculate the cell potential for a voltaic cell made from these two systems: 0.78.

Cu+2 + 2e → Cu E = 0.52 V

Ag+1 + 1e Ag E° = 0.80 V

options:

A)

0.28 V

B)

–1.32 V

C)

1.32 V

D)

–0.28 V

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Investigate: Press Reset. Start with 2.000 moles of sulfur, then press Start. How many atoms do you think this amount represents

Answers

Answer:

1.204428 * 10^24 atoms

Explanation:

Number of moles = 2 mol

Number of atoms = ?

The relationship between moles and atoms is given by the avogadro's umber. This is the number of units in one mole of a substance.  The units can be atoms, ions etc In this case it is atoms. The number is equal to  6.02214076 * 10^23

This means;

1 mol = 6.02214076 * 10^23

2 mol = x

Upon solving for x,

x = 2 * 6.02214076 * 10^23

x = 12.04428 * 10^23

x = 1.204428 * 10^24 atoms

Give an example of chemical reaction that occurs in everyday life

Answers

Answer: metal and salt water

Explanation: salt starts to brake down metal and metal is everywhere in the ocean hope this helps

Answer:

baking a cake.

Explanation:

baking a cake is an example of a chemical reaction that happens daily because a new substance is forming when the cake is being baked. hope this helps! :)

How many moles of NaHCO3 are there in a 3g tablet of Alka-Selzer?

Answers

We then need to find the molecular weight of sodium bicarbonate (NaHCO 3), which comes out to 84g/mol. To find the number of moles of sodium bicarbonate, we divide the mass of sodium bicarbonate in the tablet (1.916g) by the molar mass (84g/mol). This gives us 0.0228 moles of sodium bicarbonate in one tablet.

Why do gases spread throughout the air, but liquids or solids stay together?

Answers

Answer:

In gases are much more spread out than in solids or liquids. They vibrate and move freely at high speeds. A gas will fill any container, but if the container is not sealed, the gas will escape. Gas can be compressed much more easily than a liquid or solid.

Explanation:

gas molecules are far apart from each other which indicates spreading

Which correctly lists three characteristics that are used to describe air?

O Altitude, density, radiation

O Density, radiation, mass

O mass, pressure, density

O pressure, altitude, radiation

Answers

Answer:

Mass Pressure and density.

Explanation:

What is Darwin's name for species that do not appear to have changed for millions of years?

Answers

Since, the options have not been given the question is incomplete.

What is Darwin's name for species that do not appear to have changed for millions of years?

a.

Dinosaurs

b.

Living fossils

c.

Old souls

d.

Ancient moderns

Answer: b. Living fossil

Explanation:

In 1859 Charles Darwin proposed the term living fossil, that means a species or group of species that had not changed in terms of evolutionary context thus can be useful in tracing the extinct or previously existing forms of life. The examples of the living fossils are horseshoe crabs, ginkgo (Conifers) and tuatara. These group of animals were existed unchanged in the Ordovician, Permian, and Triassic periods respectively with few surviving species.

Answer:

the answer is living fossils so it would be b

Explanation:

how do i know i took the test

Which of these is not a property of minerals?

A) Clevage
B) Fracture
C) Color
D) Smell

Answers

The answer is D - smell.

The atomic number tells the number of

Answers

The atomic number refers to tell if the number has the amount of protons for a nucleus in an atom. This is shown that the chemical effects of an element has in its singular form in the periodic table

30 POINTS HELP Which idea was supported by Aristarchus, Copernicus, and Galileo?

The planets have epicycles.
The planets revolve around the Sun.
The stars rotate around the Sun.
The center of the solar system is Earth.

Answers

Answer:

SO SORRY it took so long but the answer is B :)

Explanation:

Trust me and good luck :)

The theory that the planets move around the sun was endorsed by Aristarchus, Copernicus, as well as Galileo. The solar system revolves around the sun.

What is Aristarchus?

Aristarchus of Samos was just a Greek astronomer that suggested the very first heliocentric model of the cosmos, wherein the sun, rather than the earth, was even at its center. Despite the fact that his hypothesis was acknowledged by other philosophers of the time, it was dismissed as unrealistic, and the geocentric model remained in use for the next 1,700 years.

What is Copernicus?

Copernicus was also the first to assert that the Earth as well as the other planets orbit the sun. It was really a significant shift in thinking.

What is sun?

Sun can be considered as a star in solar system.

The theory that the planets move around the sun was endorsed by Aristarchus, Copernicus, as well as Galileo. The solar system revolves around the sun.

Therefore, the correct answer will be option (b).

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What do you think went well last semester in your chemistry class?

Answers

This seems like more of a you thing, but give me brainliest anyways. >:D

I think I passed everything it’s going alright
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A solution with a pH value between 1 and 6 5. third term of (3x - y)5 And I also dont know how to do this. Select the correct answer.If the zeros of a quadratic function are 3 and 8, what are the factors of the function?.(X + 8) and (x - 3)OB.(x - 8) and (x + 3)O C.(X + 8) and (x + 3)OD.(x - 8) and (x-3) Sometimes a cell is compared to a city. How would the energy needs of a cell be compared to the energy needs of a city? Which of the following parts of the body are involved in the peripheral nervous system? Select all that apply.cranial nervesspinal nervesnervesgangliaplexuses Determine if the ordered pairs represent a function. Yes No{(1,3), (4, 12), (5, 15), (6, 18)} help please it's very much appreciated Which of the following best describes a player's role in any game?O A. The name of his or her character.O B. The number of turns he or she gets to take.O C. The way he or she scores points.O D. The actions expected of him or her. find the slope it is due today Introduction on where you want to visit What is the best definition of dialect? will pay give me your cash appa way of speaking that makes the actors lines easier to heara way of speaking that is specific to a certain group or locationa method of acting that relies on an actors own experiencesa method of acting that helps the audience follow the plot what happens to homeostasis as we get older? How many moles are in 43 grams of lithium (LI)? There are six dimensions of health: physical, mental, emotional, social, spiritual, and environmental. On a scale of 1-10, with 10 being optimal wellness, how would you rank each of the dimensions as they relate to your life right now, and what steps could you take to improve your overall health? Please write at least a paragraph! Help me out...p l e a s eIn a right triangle, the length of one leg is 4 units. The length of the other leg is 5 units. What is the length of the hypotenuse?A.) 3 Units B.) [tex]\sqrt18[/tex] units C.) [tex]\sqrt20[/tex] units D.) [tex]\sqrt41[/tex] units answers for the 2 boxes please WHICH OF THE FOLLOWING IS AN EXAMPLE OF ASEXUAL REPRODUCTION? (MULTIPLE ANSWERS) aMitosisbMeiosisBuddingdBinary FissioneRegeneration please help me with this question!! Kai can walk 2 miles in a half of an hour. How far will he walk in 2 hours?