HURRRY ASAP!!
An important consideration of the medical use of radioisotopes is how long they're active. Technetium-99 is a short-lived isotope of technetium with a half-life of 6 hours. If a patient is treated with technetium-99 for a PET scan, when will the patient have less than 1 percent of the original technetium-99 present?

A)

3 days

B)

40 hours

C)

6 hours

D)

0.00116 hours

Answers

Answer 1
The answer is A 3 days.

Related Questions

*
5. Gravitational potential energy is found in
(1 Point)
a rubber band pulled back ready to be shot
an apple falling from a tree branch
a boy on a skate board gliding up a ramp
a book held high over a desk

Answers

Answer:

A book held high over a desk

Explanation:

Gravitational potential energy, or GPE, is like height energy. The higher up an object is placed, the more GPE it has. Gravitational potential energy is the potential of a certain mass relative to another due to gravity. In this case you have a book held high over a desk and therefore since it's higher up it's going to have more potential energy due to gravity, which is why it has gravitational potential energy. Therefore your answer is "a book held high over a desk".

Which prefix indicates a molecule with 2 carbon atoms?
O A. Eth-
O B. Oct-
O c. Hex-
O D. Meth-


The answer is A.Eth-

Answers

The answer is A. Eth-

The prefix indicates a molecule with 2 carbon atoms is eth- and the correct option is option A.

What is IUPAC Nomenclature?

The IUPAC system of nomenclature is a set of logical rules framed which are mainly aimed at giving an unambiguous name to an organic compound.

IUPAC stands for International Union of Pure and Applied Chemistry

A prefix to the name comes before the molecule. The prefix of the molecule's name is based on the number of carbon atoms.

For example, a chain of six carbon atoms would be named using the prefix hex-.

The suffix to the name is an ending that is applied that describes the types of chemical bonds in the molecule.

Therefore, The prefix indicates a molecule with 2 carbon atoms is eth- and the correct option is option A.

Learn more about IUPAC Nomenclature, here:

https://brainly.com/question/30086566

#SPJ7

At the midpoint of a titration curve ________. At the midpoint of a titration curve ________. The concentration of a conjugate base is twice that of the concentration of a conjugate acid The pH equals the pKa The ability of the solution to buffer is at its least effective The concentration of a conjugate base is 1/2 that of the concentration of a conjugate acid

Answers

Answer:

The concentration of a conjugate base is twice that of the concentration of a conjugate acid

Explanation:

This is because at the midpoint, the number of moles of acid equals half the number of moles of base at the midpoint. This means that at the midpoint, half the analyte has been titrated.

Since the concentration of the conjugate acid is half that of the conjugate base at the midpoint, this implies that the concentration of the conjugate base is twice that of the conjugate acid.

Thus, at the midpoint of a titration curve the concentration of a conjugate base is twice that of the concentration of a conjugate acid

The half-life of strontium-90 is about 29 years. How many half-lives have elapsed when 6.25% of

O 1

02

3

оо

Answers

The question is incomplete, the complete question is;

The half-life of strontium-90 is about 29 years. How many half-lives have elapsed when 6.25% of a strontium- 90 sample remains in the container?

Answer:

4 half lives

Explanation:

From;

N/No = (1/2)^t/t1/2

N= amount of strontium-90 present at time t

No= amount of strontium-90 originally present

t= time taken

t1/2 = half life of strontium-90

But N= 0.0625No

Hence;

0.0625No/No = (1/2)^t/29

0.0625 = (1/2)^t/29

(1/2)^4 = (1/2)^t/29

4 = t/29

t = 4 × 29

t= 116 years

Hence four half lives have elapsed

calculate the oxidation numbers of the elements in this equation
2 Al2O3 → 4 Al + 3 O2

Answers

Explanation:

Answer

Open in answr app

The rule used here is that the algebraic sum of the oxidation numbers of all the atoms a molecule is zero.

Al2O32× ( oxidation number of Al)+3× ( Oxidation number of O )  = 0

2× ( Oxidation number of Al) +3(−2)=0

2× ( oxidation number of Al) +6

∴ Oxidation number of Al =+3

PLEASE HELP!!

What is the reduction half-reaction for 2Mg + O2 —> 2MgO?

A) Mg -> Mg2+ + 2e-
B) O2 + 4e- -> 2O2-
C) Mg2+ + 2e- -> Mg
D) 2O2- -> O2 + 4e-

Answers

Answer:

O2 + 4e- -> 2O2-

Explanation:

You have to start by assigning the oxidation numbers, which eventually will lead to every atom of oxygen taking 2 electrons and every molecule of oxygen will take 4 electrons.

(you can ignore this explanation, my answer wasn't long enough).

the six gas laws ASAP PLS

Answers

Charles law, Boyle’s law, and Avogadro’s law, Gay-Lussac’s law

Chloe’s teacher gives her and her lab partner soil samples from different parts of the city: the park, the area next to a pond, the school, and a neighborhood. Chloe’s teacher also gives her a soil tester kit, which determines the pH of the soil. Chloe and her lab partner need to determine the pH of each soil sample and then compare them.
Fill in the blank with the word that best completes the statement.

This investigation is a(an)______investigation.

Answers

Answer:

an

Explanation:

It is AN because investigation starts with I ( i is a vowel). When there are vowels we use An.

Pls mark me brainliest!

calculate the mass m of 6.50 moles n of kbr m

Answers

Answer:

773.51495 grams

Explanation:

1 moles KBr to grams = 119.0023 grams

6.5*119.0023 = 773.51495 grams

what are microorganisms
Please i really wanna know ​

Answers

Answer:

Are the organism we cant see with our bare eyes. We only see them with the help of a microscope

Explanation:

A microorganism, or microbe, is a microscopic organism, which may exist in its single-celled form or a colony of cells.

examples of metal non-metal and semi metal​

Answers

Answer:

Semi : Boron [B] Non-Metal : Carbon [C] Metal : Manganese [Mn]

Explanation:

Periodic table I'm guessing!

A wheelbarrow can be used to help lift a load, such as a pile of dirt, and then push the load across a distance.

A man pushes a wheelbarrow.

Which simple machines make up a wheelbarrow?

a pulley and an inclined plane
a wheel and axle and a lever
a pulley and a wheel and axle
a lever and a wedge

Answers

Answer: it consists of two simple machines: a lever and a wheel and axle. Effort is applied to the lever by picking up the handles of the wheelbarrow.

Explanation:

Answer:

B

Explanation:

B)

Which row represents an ion?
number of
protons
number of
neutrons
number of
electrons
А
1
0
1
B
3
4
3
C С
6
6
6
D
11
12
10​

Answers

Answer:

12123456789012347698

Geometric isomers have profound effects on the physical properties of compounds. Naturally occurring fatty acids generally adopt a cis geometry. What's one physical property affected by this geometry? (HELP ASAAAP!)

A)

Color

B)

Taste

C)

Smell

D)

Melting point

Answers

B.)

Taste yayququwiiqqiiqiqiwiw

Answer:

melting point

Explanation:


[tex]what \: is \: acid \: \: \: {?} [/tex]

Answers

meaning:An acid is a chemical substance, usually a liquid, which contains hydrogen and can react with other substances to form salts. Some acids burn or dissolve other substances that they come into contact with.

Answer:

Hope it help you#CarryOnLearning

list 8 functions of petroleum​

Answers

Petroleum is used as a fuel to power vehicles and machines.

Petroleum products include fuel oils for heating and electricity generation.

It is a feedstocks for making the chemicals and plastics.

We use petroleum to produce electricity.

Which of the following demonstrates how chemicals can help the environment?
A. Herbicides can get rid of unwanted weeds.
B. Pollutants can be prevented from entering the environment.
C. Pesticides can kill insects that eat garden plants.
D. Lime can be used to adjust the pH in lakes that are too acidic.

Answers

The answer is D it’s d

To solve this we must be knowing each and every concept related to environment.  Therefore, the correct option is option D among all the given options.

What is environment?

A basic definition of such an environment is a system that includes all abiotic and biotic components that impact human existence. All flora and animals are biotic components, whereas abiotic components comprise water, sunshine, air, temperature, and so on.

An environment's resources might be any issue, service, or specifics that are beneficial to society and humans. They might be anything that meets the demands of daily living.   Lime can be used to adjust the pH in lakes that are too acidic demonstrates how chemicals can help the environment.

Therefore, the correct option is option D.

To know more about environment, here:

https://brainly.com/question/28962722

#SPJ2

_ As + _ NaOH → _Na3ASO3 + __ H2

Answers

Answer:

2As + 6NaOH =2Na3AsO3 +3H2

Explanation:

2As + 6e- = 2As³ ,this is an oxidation reaction

6H¹ +6e- =6H⁰ ,this is reduction process

the above reaction exhibit a redox redox reaction As acts as a reducing agent while NaOH acts as an oxidizing agent.

Which property can be attributed to an ideal gas?

A The particles occupy a significant volume.

B The collisions of the particles are elastic.

C The particles move at different velocities.

D The particles move in definite patterns.

Answers

B The collisions of the particles are elastic

Select the statement that is most correct regarding chemical bonds. A. multiple bonds between two atoms are not possible with covalent bonding B. hydrogen bonds are very weak and can only occur when polar covalent bonds are present C. Ionic bonds involve the sharing of electrons D. Covalent bonds involve the transfer of one or more electrons from one atom to another

Answers

Answer:

hydrogen bonds are very weak and can only occur when polar covalent bonds are present

Explanation:

Hydrogen bonds are weak intermolecular interactions that occur when hydrogen is covalently bonded to a highly electronegative atom.

Owing to the difference in electro negativity between hydrogen and the highly electronegative atom, the bond is a polar covalent bond.

This hydrogen bond is a weak bond but accounts for properties such as high melting and boiling points of small molecules such as water and ammonia.

¿Cuál de los siguientes valores es igual a 1 micrómetro?
O 0,000001 metro
O 0,001 metros
O 1.000 metros
O 1.000.000 metros

Answers

La respuesta es : 0,000001 metro.

What happens to the intensity of light emitted from stars the further away the star is from us?

Answers

Answer: stars vary in their effective temperature and colour. A hot star radiates more energy per second per metre surface area than a cooler star. Does this then mean that a hot star is going to appear brighter to us than a cooler one? The answer to this actually depends on a few factors

Explanation: pa brainiest po

Describe two situations in which you observed or performed an energy transformation. For each situation, name the starting form of energy and an ending form of energy.

Answers

Answer:

The Sun transforms nuclear energy into heat and light energy.

Our bodies converting chemical energy in our food into mechanical energy for us to be able to move.

An electric fan transforming electrical energy into kinetic energy.

A circuit is set up with two parallel resistors, each of a resistance of 250Ω.
b. If another resistor of resistance 300Ω is added in series with these two parallel resistors, what is the total
resistance?
c. If a voltage of 120V is put across the circuit in b, what will the current be in the circuit?

Answers

Answer:

425 and 0.28A

Explanation:

Resistance for resistors in parallel

1/ R = 1/250 +1/250

=0.008

R = 1/ 0.008 = 125

Total resistance

R= 125+ 300

=425

...

V= IR

I= V/R

I = 120/425

= 0.28 A

Based on the enthalpy changes given for the reactions, which reactions are endothermic?

Answers

Explanation:

yan po sana makatulong

pa brainliest na din po thanks

PLEASE HELPP!!

What is the empirical formula of the compound is C22H44O22

A. CH2O

B. C3H6O3

C. C2H4O2

D. CHO

Answers

Answer:

The answer is C

A 12 inch object is placed 30 inches in front of a plane mirror

Answers

Answer:

12 inches

Explanation:

i got it right in the Same question

Which of the following represents an element ? H2O H2 NaCl CaCO3

Answers

Answer:

H₂

Explanation:

H₂ is hydrogen in its elemental form.

H₂O, NaCl, and CaCO₃ are all examples of elements added together to create compounds.

Vhon Anadome
Atomic nucleus questions
Which of the following decay processes results in the largest change in mass of a nucleus?
Choose 1 answer:
А
Beta decay
Gamma decay
Neutron emission
D
Alpha decay

Answers

Answer:

d

Explanation:

You are given 3 unknown solutions with pH value as 6, 8 & 9.5 respectively. Which solution will contain maximum OH ion

Answers

The answer is 9.5 one as it is more basic so it contains more OH ion
Hope it helps : )
Other Questions
gabby volunteers at an animal shelter. Last month she volunteered 1 3/4 hours on each of 3 Saturday. She also volunteered 3/4 hour on 4 Wednesday evenings. How many hours of volunteer work did Gabby put in last month. Which line from the neighbor MOST directly supports thetheme of the story?The Reluctant Neighbor"I know I haven't been veryfriendly.By Clara Bohrod"Well, I guess I've takenself-reliance to an extreme."1 Coco was excited to meet her new neighbor, a tall, thinwoman with elegant gray hair. To welcome her, Cocoand her mother baked their special double chocolatecookies. As they rang their neighbor's doorbell, Cocoimagined how the woman's face would light up whenshe spied the yummy treats. After what seemed likeforever, the door creaked ajar, and the woman tilted herhead to peek through the crack"Since my husband's death,I've had to rely on myself, ...""But I'm perfectly capable oftaking care of my own yard,thanks just the same."1 of 8 Select the sentence that correctly replaces the indirect object in this sentence with an indirect object pronoun: J'ai parl avec Philippe. A. Je les ai parl. B. Je l'ai parl.C. Je lui ai parl. which graph is a function of x? Which of the following people should not eat a vegetarian diet? A. Wrestlers B. Bodybuilders C. Anyone can be a vegetarian and still be strong D. Runners Find the indicated Arc length in bold . Use 3.14 for pi! if the sun is a source of EM radiation , how come only some of the EM strikes the surface of the earth When did people first know about archaebacteria?A. 1999B. 1988C. 1977D. 1966 What is the correct way to rewrite this sentence? A. Rachel passed the store where her mom worked; on her way to school. B. Rachel passed, the store where her mom worked on her way to school. C. Rachel passed the store, where her mom worked, on her way to school. D. Rachel passed the store where her mom worked on her way to school. Why did the Framers of the Constitution envision immediate action from the executive branch but slower deliberation in Congress? What is one advantage and one disadvantage of each type of decision making? What the hell is a conjugation someone lease explain Small, reduced leaves with a single vein occurring in the club mosses You hold currency from a foreign country. If that country has a higher rate of inflation than the United States, then over time the foreign currency will buy a. more goods in that country and buy more dollars. b. more goods in that country but buy fewer dollars. c. fewer goods in that country but buy more dollars. d. fewer goods in that country and buy fewer dollars. 80 POINTS HURRY ILL GIVE BRANLIEIST!!!A landscape architect built a square playground. The outside edges of the playground measure 3x meters. The playground has an area of 8100 m^2. How much fencing is needed to fully enclose the playground? Find the equation of a line containing the points (5,1) and (5,4). was diane nash involved in sit ins During May, Carolan Corporation transferred $59,000 from Work in Process to Finished Goods and recorded a Cost of Goods Sold of $65,000. The journal entries to record these transactions would include a: Multiple Choice credit to Cost of Goods Sold of $65,000. debit to Finished Goods of $65,000. credit to Work in Process of $59,000. credit to Finished Goods of $59,000. Match each type of figurative language with its example.personificationThe donut holes were bigger thanbaseballssimileThe sunset looked like pink cottoncandymetaphorThe clouds wept.hyperboleThe fan was a tornado, sending thepapers flying out the window.Done5) Intro Which of the following is NOT a general education elective area? Group of answer choices Fufufu with me peasantsFufufu~030