How much of a sample remains after five half-lives have occurred?
1/5 of the original sample
1/25 of the original sample
1/32 of the original gample
1/64 of the original sample

Answers

Answer 1
The answer is 1/32

The first half-life, we have 1 • 1/2 = 1/2 left.
After two: 1/2 • 1/2 = 1/4
Three: 1/4 • 1/2 = 1/8
Four: 1/8 • 1/2 = 1/16
And five: 1/16 • 1/2 = 1/32.
Answer 2

Answer:

1/32

Explanation:


Related Questions

****URGENT****
I need help!!!
the answers are there, i need someone to explain please!

Answers

Explanation:

your answer was correct

Chemistry!! Help me! And explain step by step!

Answers

1st part is ure answer --> 2M

Given mass -> 58 grams

mass of NaCl -> 58.44 approx -> 58 any

moles given-> 1 moles

[tex]Molarity = \frac{moles}{vol \: in \: lts} [/tex]

[tex]Molarity = \frac{1}{0.5} = \frac{10}{5} \\Molarity = 2M[/tex]

3. An atom
OF
elemente A has mass number 39 and 19 protons
Write the electron arrangement of the atom


Answers

Answer:

Explanation:

Potassium (K) atom has 19 electrons. The full electron configuration of Potassium (K) is 1s22s22p63s23p64s1

Principal energy level

Quantum number: n

1

2

3

4

5

6

Sublevels

availableQuantum number: l

1s

2s 2p

3s 3p 3d

4s 4p 4d 4f

5s 5p 5d 5f 5g

6s 6p 6d 6f 6g 6h

3. What would be the freezing point for a 5.7 molal aqueous sucrose (C12H22O) solution? The freezing
point depression constant for water = 1.86°C/m. Show your work.

Answers

Answer:

- 10.6° C

Explanation:

Given that,

In the aqueous sucrose solution,

Molality of the solution (m) = 5.7

Freezing point constant (K) = 1.86

To find,

The freezing point of the solution = ?

Method:

To find its freezing point, we will first find out if the solute demonstrates an electrolyte or not.

In case it is not, the van't Hoff factor i.e. ration of particles' concentration denoted by (i) would be taken as 1. So,

ΔT(change in temperature) = i * m * K              (putting the given values)

= 1 * 5.7 * 1.86

= 10.6° C

Thus, the freezing point equals to 0 - 10.6° C = -10.6° C.

What is the name for the compound li2so4

Answers

Answer:

Explanation:

Lithium Sulphate

Answer:

Lithium sulfate is a white inorganic salt with the formula Li2SO4. It is the lithium salt of sulfuric acid.

what is precipitating ???


anyone please tell me how to delete an I'd ​

Answers

Explanation:

Desposition of solid matter in a solution

What is te SI unit of time?

Answers

Answer:

second (S) is the SI unit of time.

Answer:

second

Explanation:

the gap between any two intervals is called time

time can be measured in hour,minute,second

but second is the SI unit of time

Potassium impart purple colour but beryllium do not impart any colour to the flame.Why?​

Answers

Answer:

The electrons in beryllium and magnesium are too strongly bound to get excited by flame. Hence, these elements do not impart any color.

Một hỗn hợp X gồm CH3OH; C2H5OH; phenol có khối lượng 28,9 gam phản ứng vừa hết với 100ml dung dịch NaOH 2M. Phần trăm theo khối lượng phenol là ? Biết C = 12; O = 16; H = 1; Na = 23. *

Answers

Answer:

nNaOH = 0,2 mol

Trong hỗn hợp các chất đề bài cho chỉ có phenol tác dụng với NaOH

C6H5OH + NaOH → C6H5ONa + H2O

   0,2  ←     0,2 (mol)

⟹ mphenol = 0,2.94 = 18,8 gam

⟹  

%mC6H5OH=18,8/28,9 x100%= 65,05%

Explanation:

A sample of gas occupies 1.2 L at 12.0oC. Assuming pressure remains the same, what would be the volume (in L) of this gas at 67oC?

A.
1.4

B.
1.0

C.
0.2

D.
5.0

E.
6.7

Answers

Answer:

e.

6.7

hope it help

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Which atom's ionization energy is greater than that of phosphorus (P)?
A. Ba
B. K
C. As
D. CI

Answers

Answer:

Chlorine

Explanation:

the ionization increases as you get closer to the top right. since chlorine (Cl) is the only one of the answer choices that is closer to the top right corner compared to phosphorous (P), that is the answer.

Answer:

cl

Explanation:

because ionization energy decrease from left to right

Balance the following equations

Answers

ANSWER

2Ba + 2HBr → 2BaBr + H2

2BiCl3 + 3H2S → Bi2S3 + 6HCl

Br2 + 2KI → I2 + 2KBr

4Fe + 3O2 → 2Fe2O3

I HOPE THIS WILL HELP YOU IF NOT THEN SORRY HAVE A GREAT DAY:)

Answer:

[tex]3Mg _{(s)} + N _{2(g)} → Mg_{3} N _{2(s)}[/tex]

[tex]Ba _{(s)} + 2HBr_{(g)} → BaBr _{2(s)} + H _{2(g)}[/tex]

[tex]2BiCl_{3(s)} + 3H_{2} S _{(g)} → Bi _{2} S _{ 3(g)} + 6HCl _{(g)} \\ [/tex]

[tex]Br_{2(g)} + 2KI _{(g)} → I _{2(g)} +2 KBr _{(g)}[/tex]

[tex]4Fe_{(s)}+ 3O_{2(g)} → 2Fe_{2} O _{3(s)} [/tex]

Which statement describes the law of conservation of energy?
All systems will exchange matter and energy with their surroundings.
All systems can exchange energy, but not matter, with their surroundings.
Energy cannot be created nor destroyed, but it changes from one form to another.
Energy is destroyed in most chemical reactions when new products are formed.

Answers

Answer:

All systems will exchange matter and energy with their surroundings.

Explanation:

Answer:c

Explanation:

Are you ready kids?

Aye, aye Captain.

I can't hear you!

AYE, AYE CAPTAIN!

Oooooooooh.

Who lives in a pineapple under the sea?

Spongebob squarepants!

Absorbent and yellow and porous is he?

Spongebob squarepants!

If nautical nonsense be something you wish!

Spongebob squarepants!

Then drop on the deck and flop like a fish!

Spongebob squarepants!

Ready?

Spongebob squarepants.

Spongebob squarepants.

Spongebob squarepants.

Spongebob squarepants.

Spongebob-squarepants.

A new stable element with an atomic number of 120 and an atomic mass of 246 is created in a particle accelerator. Enough of this element is created to determine that it combines with chlorine in a 1:2 ratio. Element 120 should be placed in the same group as _____ on the periodic table.

Answers

Answer:

Be,Mg,Ra etc

Explanation:

It should be palced in group 2A because as it reacts with chlorine in ratio of 1:2 . It's valancy is 2 and is metal as it react with non metal donating two electrons .

one more thing it fits there orderly


Which of these solutions is acidic?

Answers

Answer:

Option a is a solution acidic ([OH⁻] = 7.0x10⁻⁹ M).

Explanation:

To know if a solution is acidic we need to calculate the pH and it must be lower than 7. A value of pH equal to 7 is a neutral solution and a solution with a pH value higher than 7 is a basic solution.

a. For the [OH⁻] = 7.0x10⁻⁹ M we have:

[tex] pOH = -log[OH^{-}] = -log(7.0 \cdot 10^{-9}) = 8.15 [/tex]

Now, the pH is:

[tex] pH + pOH = 14 [/tex]

[tex] pH = 14 - pOH = 14 - 8.15 = 5.85 [/tex]

This solution is acidic (pH < 7)

b. [H₃O⁺] = 8.5x10⁻⁸ M

[tex] pH = -log(8.5 \cdot 10^{-8}) = 7.07 [/tex]

This is not an acidic solution. Is a neutral one (pH around to 7).

c. [OH⁻] = 2.5x10⁻⁶ M

[tex] pOH = -log[OH^{-}] = -log(2.5 \cdot 10^{-6}) = 5.60 [/tex]

Then, the pH is:

[tex]pH = 14 - pOH = 14 - 5.60 = 8.40[/tex]

Hence, this is not an acidic solution. It is basic (pH > 7).    

Therefore, option a is a solution acidic ([OH⁻] = 7.0x10⁻⁹ M).

I hope it helps you!

Some species form social groups only with members of the same gender. For example, elephants form groups with
only females and their offspring. Once the male offspring reach a certain age, they leave the group and become
solitary.
Which is a benefit of this type of social group structure?

Answers

Explanation:

For example, elephants form groups with only females and their offspring. Once the male offspring reach a certain age, they leave the group and become solitary. Which is a benefit of this type of social group structure? A:Females do not have to compete for a mate.

can you solve this science question ⁉️​

Answers

Answer:

chemical reaction between those a b c it's a reaction which occurs when heating

PLZ HELP ME WITH MY WORK
What is a compound?
A substance that is made from two different metals
B. A substance that cannot be broken into simpler substances
C. A substance that is made using a chemical reaction
D. A substance that can be separated by physical means​

Answers

Answer:

C.

Explanation:

Answer A is incorrect because a compound doesn't have to be made with only metals.

Answer B is incorrect because that is actually the definition of a pure element.

Answer C is correct because to make a compound, there has to be a chemical reaction where bonds are formed and an entirely new substance is created.

Answer D is incorrect because compounds cannot be separated by physical means.

Hope this helps :D

Which of the following is an example of combustion?
O A. potassium chlorate -> potassium chloride + oxygen
B. aluminum + cobalt chloride -> aluminum chloride + cobalt
O c. hexane + oxygen carbon dioxide + water
OD. sodium cyanide + hydrochloric acid -> sodium sulfate + hydrogen cyanide

Answers

The answer is c hexane+oxygen carbondioxide+ water

What is the solubility of salt at 60°C if 2 gm of the salt is left behind when 7 gm of its saturated solution at that temperature dried?
a) 20
b) 40
c) 60
d) 80 ​

Answers

40

Explanation:

because its Saturated

Câu 9: 100 g dung dịch MgCl2 9.5 % tác dụng đủ với dung dịch KOH 5,6 % .được dung dịch A và chất rắn B. Lọc rắn B và nung đến khối lượng không đổi được chất C.
a) Viết pt .Tính khối lượng răn C
b) Tính nồng độ phân trăm của dung dịch A.

Answers

hiiiiiiiii

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22.5 ml of a 0.200 m HBr solution was added to a 50.00 ml sample of 0.250 m sodium benzoate (NaC7H5O2). Calculate the pH. Benzoic acid has a Ka 6.30 x 10-5.

Answers

In this problem, we need to find the pH of a buffer (pH = 4.45) that is produced by the reaction of strong acids as HBr that reacts with weak bases as NaC₇H₅O₂ producing its weak acid and a salt, as follows:

HBr + NaC₇H₅O₂ → HC₇H₅O₂ + NaBr

If in the reaction, the limiting reactant is the strong acid, we will produce a buffer (The aqueous mixture of a weak acid and its strong base).

Using Henderson-Hasselbalch equation, we can find the pH of this buffer:

[tex]pH = pKa + log \frac{[NaC_7H_5O_2]}{[HC_7H_5O_2]}[/tex]

Where:

pKa is -log Ka = 4.20

[] could be taken as the moles of each species

After the reaction, the moles of HBr = Moles of HC₇H₅O₂ and the remaining moles of NaC₇H₅O₂ = Initial moles of NaC₇H₅O₂ - Moles of HBr.

Moles HBr:

22.5mL = 0.0225L * (0.200mol/L) = 4.5x10⁻³ moles HBr

Moles NaC₇H₅O₂:

50.0mL = 0.0500L * (0.250mol/L) = 0.0125 moles NaC₇H₅O₂

That means the moles after the reaction of the species of the buffer are:

Moles HC₇H₅O₂ = Moles HBr = 4.5x10⁻³ moles

Moles NaC₇H₅O₂ = 0.0125 moles - 4.5x10⁻³ moles = 8.0x10⁻³ moles

Replacing in H-H equation:

[tex]pH = 4.20+ log \frac{[8.0x10^{-3}]}{[4.5x10^{-3}]}[/tex]

pH = 4.45

Learn more about Henderson-Hasselbalch equation in:

https://brainly.com/question/13423434

what is the product of SO2+H2O. ​

Answers

Answer:

H2O + SO2 → H2SO3

Explanation:

H2O + SO2 → H2SO3

Answer:

l think this is the answer .

A scientist claims that the water molecules that you drink today could be millions of years old. Use evidence from the water cycle to support the scientist’s claim.

Answers

Answer:

As water on the surface of lakes, oceans, and rivers warms up, it travels into the sky as very tiny droplets, or vapor. When the water vapor gets colder, it turns back to liquid to help form clouds.

When the liquid gets so heavy it can’t stay in the atmosphere anymore, it falls, or “precipitates,” as rain, snow, sleet, hail, or, my favorite, graupel. Once the precipitation reaches the ground or lands in lakes, oceans, and rivers, the cycle continues.

Explanation:

A scientist claims that the water molecules that you drink today could be millions of years old in the water cycle the new clouds athat re made cannot rain but the clouds which are old do rain.

What is the water cycle?

The water cycle or cycle of water is the journey of each and every water molecule by which it is made up of as the clouds in the environment are made up of the evaporation process in the environment.

The vapors of evaporation condense in the environment to form the clouds and these clouds are only responsible for the rain but the old and heavy clouds can only do it.

Therefore, in the water cycle, the new clouds are made cannot rain but the clouds which are old do rain scientist claim that the water molecules that you drink today could be millions of years old.

Learn more about the water cycle, here;

https://brainly.com/question/1151425

#SPJ2

Uranium-235 and uranium-238 are different ________ of uranium
(Apx answers please)

Answers

Answer:

Isotopes

Explanation:

An isotope are the atoms of an element with similar chemical identity and number of protons but different atomic masses. This means that isotopes of an element differ from one another by their number of NEUTRONS.

For example, the uranium element possesses isotopes as follows: Uranium-235 and uranium-238. This two isotopes have the same chemical identity and number of protons/atomic no., which is 92. However, the atomic masses (235 and 238) are different.

Answer:

Isotopes

Explanation:

Suppose you had a valuable collection of small diamonds, which you kept safe from the thieves by mixing them with white sugar crystals. You store the mixture in a jar labeled 'sugar'. Now you want to sell the diamonds. Describe how you would separate all the diamonds from the sugar.

Answers

Answer:

Pour the sugar/diamond mixture into a container of water and stir until the sugar is dissolved completely. Then strain the mixture and wash the diamonds with water.

Answer:

Stir with a large enough volume of cold water to dissolve all the sugar. Filter to leave the diamonds on the filter paper. Wash on the filter paper with more water to remove any last traces of sugar solution. Allow to dry.

Convert the following moles to grams :)
1. 2.4 moles sulfur
2. 1.5 moles BeI2
3. 7.5 moles C6H12O6

Answers

Answer:

3

Explanation:

sky is high and I am good.

hii pls help me to balance the equation thanksss​

Answers

Explanation:

2KCLO3 (s) = 2KCl (s) + 3O2 (g)

please answer this questions soon

i will mark him or her brillient

Answers

Answer:

1)Or

d.Sublimation

2)

b.iodine is the solute and alcohol is solvent

3)

a.compostion of solute

Answer:

1) a) centrifugation

OR

b) sublimation

2) a) iodine is the solute and alcohol is solvent

3) a) concentration of soLute

what is cytoplasm ? what does it contain?​

Answers

Answer:

Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane. It is mainly composed of water, salts, and proteins. All of the organelles in eukaryotic cells, such as the nucleus, endoplasmic reticulum, and mitochondria, are located in the cytoplasm.

Answer:

Explanation:

                             Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane. It is mainly composed of water, salts, and proteins. All of the organelles in eukaryotic cells, such as the nucleus, endoplasmic reticulum, and mitochondria, are located in the cytoplasm. ...

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