5. The Half-life of cobalt-60 is 5 years. What fraction of a sample remains after 20 years?
a.One half
b. One quarter
c.One eighth
d. One sixteenth

Answers

Answer 1
B but correct me if I’m wrong

Related Questions

What is the amount of heat absorbed when the temperature of 75 grams of water increases from 20°C to 35°C?

Answers

Answer: 4707 J

Explanation:

The quantitative amount of charge separation in a diatomic molecule contributes to the dipole moment of that molecule. A. True B. False

Answers

Answer:

The answer is True.

Explanation:

The sentence above is true it all adds up.

Which of the following identifies the part of the solution that is the dissolved substance?

A.
solvent

B.
base

C.
acid

D.
solute

By the way the answer is D if anyone searched this up

Answers

Answer: D

Explanation:

This is just a definition.

Which of the following statements is FALSE?
Compounds are combinations of different elements found on the Periodic Table
Elements are composed of two or more compounds
Elements are the building blocks of compounds
O
Elements and compounds are both types of pure substances

Answers

The false statements are the compound are combinations of the elements
Elements are composed of two or more compounds.

What is the wavelength of a photon with an energy of 4.56 x 10-19 J?
• A. 502 nm
• B. 436 nm
C. 688 nm
D. 460 nm

Answers

Answer:

B

Explanation:

We can use Planck's equation. Recall that:
[tex]\displaystyle E = h\nu[/tex]

Where h is Planck's constant and ν is the frequency.

We also have that:
[tex]\displaystyle \lambda \nu = c[/tex]

Where c is the speed of light and λ is the wavelength. Hence:

[tex]\displaystyle \nu = \frac{c}{\lambda}[/tex]

Therefore:
[tex]\displaystyle E= h\left(\frac{c}{\lambda}\right)[/tex]

Solving for λ yields:
[tex]\displaystyle \lambda = \frac{hc}{E}[/tex]

Hence substitute. Recall that h = 6.626 × 10⁻³⁴ Js and c = 2.998 × 10⁸ m/s:

[tex]\displaystyle \begin{aligned} \lambda & = \frac{(6.626\times 10^{-34}\text{ Js})(2.998\times 10^8\text{ m/s})}{4.56\times 10^{-19} \text{ J}} \left(\frac{1\times 10^9\text{ nm}}{1\text{ m}}\right) \\ \\ & = 436\text{ nm}\end{aligned}[/tex]

In conclusion, our answer is B.

When CO2 and H2O react to form H2CO3, the number of bonds broken in H2O is ____ and in CO2 is _____. one; one

Answers

CO2 and H2O react to form H2CO3 and two bonds are broken each in CO and H2O to form H2CO3.

What is chemical bonding?

Chemical bonding refers to the forces of attraction which hold atoms of the same or different elements together in order to form stable compounds or molecules .

Chemical bonding may be either ionic or covalent.

The greater the number of bonds in a compound, the more stable the compound.

During chemical reactions, bonds are broken and new binds are formed.

There are two bonds each in CO2 and H2O.

This, in the reaction between CO2 and H2O react to form H2CO3, , the number of bonds broken in H2O is two and in CO2 is two.

Learn more about chemical bonding at: https://brainly.com/question/819068

Why are engineers an important part of the space exploration team?
----------------------
OPTIONS:
A) They use state-of-the-art technology.
B) They use the information that astronauts gather to make advancements in other fields of science.
C) They design and build spacecraft, space vehicles, and satellites.
D) They help astronauts train for weightlessness and spacewalks.

Answers

A) B). That’s it I hope it’s help.

NaHCO3(s) + HCl(aq) — NaCl(s) + H2011) + CO2

teacher reacts 84. 0 g of sodium bicarbonate with excess hydrochloric acid. What is the

percent yield for sodium chloride if 56. 0 g of sodium chloride is produced?

Answers

Can u add the picture ??

derive the electric field at an axial point.

please help
don't spam​

Answers

Answer:

[tex]\huge\underline{\red{A}\blue{n}\pink{s}\purple{w}\orange{e}\green{r} -}[/tex]

before looking at what the question says ,

let's have some general information related to the topic of the question !

__________________________

[tex]\implies \: [/tex] Electric field refers to the force generated by a nearby charge in the surroundings.

__________________________

[tex]\implies \: [/tex] Mathematically ,

Electric field = [tex]\frac{Kq}{r^{2}} \\[/tex]

where ,

K = coulomb's constant

q = magnitude of charge

r = distance between the opposite terminals

___________________________

[tex]\implies \: [/tex] Dipole moment , P = 2qd

where ,

q = magnitude of charges

d = distance between the charges

___________________________

[tex]\implies \: [/tex] positive charge tends to throw the field away from it while negative charge tends to pull the field towards it !

_____________________________________

seems like enough of information , so now let's look at the derivation !

refer the attachments in order to see the derivation !

Final answer -

[tex]\bold\pink{E = \frac{2kp}{(x {}^{2} - d {}^{2} ) {}^{2} } } \\ [/tex]

while , for a short dipole

[tex]\bold\pink{E = \frac{2pk}{x {}^{3} }} \\ [/tex]

hope helpful :D

why neon is special from other chemical elements​

Answers

Answer: it has full valence shells

Explanation: Hope this is it

Answer:

Neon, along with helium, argon, krypton and xenon, make up the group known as noble gases. These are the most stable and least reactive elements due to having full valence shells (the outer shell has the max number of electrons, two for helium, eight for the rest).

Explanation:

Hope it helps

PlS MARK BRAINLIEST <3

`

`

`

Tori

sneksks ansia soaks s

Answers

Answer:

hamburger

yes yes

Explanation:

none lol

Which of these are functions of the female reproductive system but not the male reproductive system?Select three options.

nourishes a developing baby
produces reproductive cells
protects the developing offspring
serves as place where fertilization takes place
transports reproductive cells

Answers

Answer:

Hello! your answer is A,C, and D!

Explanation:

These are things only females would do/have, I hope I helped and good luck!

Have a wonderful day/night!

d) a male doesn’t have a place where fertilization can take place, only a female does

help meeeeeeeeeeeeeeeeeeeeee

Answers

Answer:

Formula of water:H2O

Formula of potassium chloride:KCl

What unusual characteristic of water gives it this relatively unique phase diagram? Explain. (Hint: think about molecular structure of solid and liquid water.)

Answers

Answer:In water's diagram, the slope of the line between the solid and liquid states is negative rather than positive. The reason is that water is an unusual substance in that its solid state is less dense than the liquid state.

Explanation:

Classify each substituent as ortho, para activators; ortho, para deactivators; or meta deactivators.

Answers

The activating groups are; -NH2, -NR2 > -OH, -OR> -NHCOR> -CH3. while the deactivating groups are;  -NO2, -CF3> -COR, -CO2R, -SO3H > Halogens.

Electrophillic substitution

Owing to the  unusual stability of the benzene ring, it does not undergo  addition like other unsaturated species, rather benzene does undergo electrophillic substitution.

The substituent groups determine whether the molecule will be activated or deactivated towards electrophilic substitution, the following groups decativate benzene towards electrophilic substitution; -NO2, -CF3> -COR, -CO2R, -SO3H > Halogens. The following groups activate benzene ring towrads electrophilic substitution; -NH2, -NR2 > -OH, -OR> -NHCOR> -CH3.

Learn more about activators and decativators: https://brainly.com/question/9904853

why don't we have a lunar eclipse every month?
PLEASE HURRY

Answers

Answer:

Beacause  it does  just in a different place

Explanation:

Why don't we have a lunar eclipse every month?

Because the Earth's orbit around the sun differs from the Moon's orbit around the Earth, lunar eclipse don't happen every month.

#LearnWithBrainly

I need help in this question pleaaaaase!

Answers

The correct definition of oxidation in terms of oxygen, electron and hydrogen is added, lost , lost, (Row B).

What is an oxidation reaction?

An oxidation reaction is a reaction in which the oxidation number if the reacting species increases in a positive direction.

Oxidation can be defined in terms of oxygen as the addition of oxygen. Oxidation can be defined in terms of electron as removal of electron Oxidation can be defined in terms of hydrogen as removal of hydrogen.

Therefore, the correct definition of oxidation in terms of oxygen, electron and hydrogen is added, lost , lost, (Row B).

Learn more about oxidation at: https://brainly.com/question/4222605

2 Which best describes an acid?

F

A. A soapy substance that is nonreactive

with metals

B. A neutral substance made of oppositely

charged particles

C. A caustic substance that has a high

number on the pH scale

D. A sour liquid that forms gas bubbles

when mixed with copper

Answers

D. A sour liquid that forms gas bubblee when mixed with copper

calculate the molar solubility of ca(oh)2 in 0.10 m ca(no3)2 (ksp= 1.3x10^-6) in pure water

Answers

Ca(OH)₂⇒ Ca²⁺ + 2OH⁻

s                 s         2s

Ksp = [Ca²⁺][OH⁻]²

Ca(NO₃)₂ ⇒ Ca²⁺ + 2NO₃⁻

0.1 M             0.1        0.2

Input in Ksp

1.3 x 10⁻⁶ = 0.1 . 4s²

s² = 3.25 x 10⁻⁶

s = 1.8 x 10⁻³

1.8 x 10⁻³ is the molar solubility. Solubility is the amount of a substance that can be dissolved in a liquid to form a solution.

What is solubility?

Solubility is the amount of a substance that can be dissolved in a liquid to form a solution; it is typically represented as grammes of solute every litre of liquid. One fluid's (liquid or gas) solubility in another can be entire (e.g., methanol and water are completely miscible) or partial (e.g., oil and water barely mix). Generally speaking, "like dissolves like" (for instance, the aromatic hydrocarbons dissolves in one another but not in water).

A material's solubility in two solvents is measured by the distribution coefficient, which is used in some separation techniques (such as absorption and extraction). In general, as temperature rises, so do the dissolution rates of solids in liquids, while they fall as temperature rises and rise with pressure for gases.

Ca(OH)₂⇒ Ca²⁺ + 2OH⁻

s                 s         2s

Ksp = [Ca²⁺][OH⁻]²

Ca(NO₃)₂ ⇒ Ca²⁺ + 2NO₃⁻

0.1 M             0.1        0.2

1.3 x 10⁻⁶ = 0.1 . 4s²

s² = 3.25 x 10⁻⁶

s = 1.8 x 10⁻³

Therefore, 1.8 x 10⁻³ is the molar solubility.

To know more about solubility, here:

https://brainly.com/question/14366471

#SPJ2

what is the total ionic and net ionic equation for for the reaction between between mercury (II) nitrate and iron (III) chloride.

Answers

Answer:

Hg+2 + 2Cl- -> HgCl2






HOPE THIS HELPS HAVE A GREAT DAY/NIGHT!!~

Explanation:

How to know if a reaction is endothermic or exothermic.

Answers

Check if there is any heat evolved. For exothermic reaction—just remember it releases energy and gives off heat for the chemical reaction!

How does an indicator differentiate between an acid and base?
Changes solubility
Changes reactivity
Changes color
Changes size

Answers

Answer:

that is all I know sorry hope that may help you :)

Explanation:

Indicator is a substance which shows different colors in acidic and basic medium. Indicators can be natural (derived from natural sources) or artificial ( man-made) for example :

*Litmus is an indicator. Acid turns blue litmus into red while base turns red litmus into blue

* Turmeric solution does not show change in color (remains yellow) in acidic solution and turns red in basic solution.

Use the table below to answer questions 3-5.
Molality (m) Potassium
Water

Molality | Potassium | Water

А | 45 g | 1600 g

5.1 | B | 3.2 kg

2.5 | 4.5 moles | C

Calculate the value of A,B and C​

Answers

Answer:

5.1 | B | 3.2 kg

Explanation:

What is the chemical formula of the phosphate ion?.

Answers

Answer: PO43

Explanation: The structure and formula are as follows: The chemical structure of phosphate is PO43-.

The molecular mass is 94.97 g/mol.

HBr+ AI(OH)3 H2O + AIBr3

Answers

This is an acid-base reaction (neutralization): Al(OH) 3 is a base, HBr is an acid. ; Colorless gas with a sharp, irritating odor. [Note: Shipped as a liquefied compressed gas. Often used in an aqueous solution.]
...
Search by products (AlBr 3, H 2O)
1 HBr + Al(OH)3 → H2O + AlBr3
2 Al2O3 + HBr → H2O + AlBr3

Which postulate of daltons atomic model was later changed and why

Answers

atom is indivisible particle and can be subdivided into smaller particles

The actual electronic structure of the molecule with individual Lewis structure resonance forms is called g

Answers

Answer:

The actual electronic structure of the molecule (the average of the resonance forms) is called a resonance hybrid of the individual resonance forms.

Explanation:

hope this help

pls mark brainliest

What is the role of conservation of momentum to your safety either as pedestrians or as motorist?

Answers

The role of conservation of linear momentum is important to your safety as a pedestrian or a motorist because you will avoid being hit by car.

Conservation of linear momentum

The principle of conservation of linear momentum states that the sum of the initial momentum of an isolated system is equal to the sum of the final momentum.

The role of conservation of linear momentum is important to your safety as a pedestrian or a motorist because you will avoid being hit by car which is in motion, knowing that impulse you will receive will be equal to the change in the momentum of the car.

Learn more about conservation of linear momentum here: https://brainly.com/question/7538238

What is the limiting reactant?
3. 0.20mol AsCl, react with 0.25mol H.O

Answers

Answer:

Explanation:

0.20/4 = 0.05 for arsenic trichloide.

0.25/6 = 0.04 for water.

This means that water is the limiting reactant.

What are 2 instruments used to test for conductivity

Answers

Answer:

Your answer is  probe and a meter.

Explanation:

Hope it helps

Good Luck

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