A sample of radioactive material starts with 80 grams. After 3 half-lives have passed, how much radioactive sample remains?

Answers

Answer 1

Answer:

I want to say 10 grams

Explanation:

80 grams is your start

and a half-life is half of that so...

half of 80 ( and or 80/2)

40 grams

then another half is...

half of 40 (and or 40/2)

20 grams

then another half-life is...

half of 20 (and or 20/2)

10 grams

That is 3 half-life of 80 grams

*becareful not to just divide 80 / 3 you will get 26.666 (repeating) that is  incorrect

you want a half of a half of a half


Related Questions

1) Compounds Y and Z both have the formula C9H18.
Both Y and Z react with one molar equivalent of hydrogen in the presence of a palladium catalyst to form 2-methyloctane.
The heat of hydrogenation of Y is less than that of Z.
Y and Z each undergo hydroboration/oxidation to give a primary alcohol (OH attached to a primary carbon).
What is the structure of Y?
2) Compound X has the formula C8H12.
X reacts with two molar equivalents of hydrogen in the presence of a palladium catalyst to form cyclooctane.
Treatment of X with ozone followed by zinc in aqueous acid gives two molar equivalents of the same dialdehyde.
What is the structure of X

Answers

Answer:

See explanation and images attached

Explanation:

We know that the cis isomer has more heat of hydrogenation since it is less stable than the trans isomer. Since the hydrogenation of both compounds yields the same product and the hydroboration/oxidation both give a primary alcohol, they are geometric isomers and Y is the trans isomer (Image 2).

For the compound C8H12, the compound in question must be 1,5- cyclooctadiene since two moles of the same aldehyde was obtained after ozonolysis and reaction with two equivalents of hydrogen gives cyclooctane (Image 1).

HELP ASAP DUE IN 5 MINUTES WILL GIVE BRAINLIEST
Energy is conserved within a system, meaning that forms of energy are either transferred or transformed as they interact with objects. Which of the statements below correctly describe how energy is transferred or transformed in daily life?
Group of answer choices

Kinetic energy transforms into thermal energy when a heating pad is turned on.

Electrical energy is transferred into light energy so that a flashlight generates light when it’s turned on.

Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street.

Nuclear energy is transferred to electrical energy to provide electricity for our homes.

Answers

Answer:

i do believe it is C. Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street. but if i am wrong plz don't come at me but i believe that is right

Explanation:

Answer:

i do believe it is C. Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street. but if i am wrong plz don't come at me but i believe that is right

Explanation:

hydrogen sulphide and water molecules have the same shape. however the bond angle in water is greater than the bond angle in hydrogen sulphide. explain this​

Answers

Answer:

Oxygen is more electronegative than sulphur

Explanation:

Bond angle of a molecule is related to the electronegativity of the central atom. The more electronegative the central atom is, the greater the bond angle.

As electronegativity of the central atom increases, the magnitude of bond pair- bond pair repulsion increases leading to increase in bond angle.

Hence, oxygen, being more electronegative than sulphur asserts a greater bond pair- bond pair repulsion leading to a greater bond angle in water.

Please answer it truthfully please​

Answers

Answer:

False

Explanation:

Chemical and Physical changes happen uniquely, they cannot happen at the same time. When you crumble a piece of paper you don't change its chemical form you change its physical form. When a piece of metal rusts its chemical composition changes, leading me to believe it is false.

Good luck on the rest of your assignment/test!

_______ are characterized by having high melting and boiling points as well as being solid at room temperature
A. Iconic lattices
B. Giant covalent structures of ionic lattices
C. Giant covalent
D. Lone pairs

Answers

Answer:

C. Giant covalent

Giant covalent are characterized by having high melting and boiling points as well as being solid at room temperature. Hence, option C is correct.

What is a covalent bond?

A covalent bond shares one or more pairs of electrons between two atoms.

Giant covalent structure:

Polythene: long chains of atoms that are able to rotate along the bonding axis.

Graphite: layers of (hexagonal) carbon sheets; each individual sheet are rigid (allows no rotation.)

Silicon dioxide: three-dimensional (tetrahedral) network of carbon and oxygen atoms; the entire network is very rigid (allows no rotation.)

Diamond: three-dimensional (tetrahedral) network of carbon atoms and is very rigid.

Hence, giant covalent are characterized by having high melting and boiling points as well as being solid at room temperature.

Learn more about covalent bond here:

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#SPJ5

Balance this equation.
_Mg +_Cl2 -->_MgCl2

Answers

Answer:

1Mg + 1Cl2 = 1MgCl2

Explanation:

Hi! When balancing an equation, you want to make sure that there are equal amounts of each element on both sides. When looking at the equation that you provided in the question, look and count how many of each element are on each side. I can see that there is 1 Mg ion on the left and 1 Mg ion on the right. There are also 2 Cl ions on the left and 2 Cl ions on the right. Because they are already equal, the coefficients in front of each compound will be 1. If the amounts were different on each side, that is when you would need to add different coefficients.

Hope this helps! Let me know if you have any other questions about this!

At room temperature (20 °C), milk turns sour in about 64 hours. In a refrigerator at 3 °C, milk can be stored three times as long before it sours.
(a) Estimate the activation energy of the reaction that causes the souring of milk.
(b) How long should it take milk to sour at 40 °C?

Answers

Answer: Since k2 corresponds to 64 hours, the time for the milk to sour at 40 C is 64 h / 9.38 = 6.8 hours.

Explanation:

At temperature T1, the Arrhenius Equation is:

k1 = Ae^(-Ea/RT1).

An equivalent equation can be written at T2:

k2 = Ae^(-Ea/RT2).

If these equations are divided, then A cancels:

k1/k2 = e^(-Ea/RT1)/e^(-Ea/RT2)

Taking the natural log:

ln(k1/k2) = (Ea/RT2)-(Ea/RT1);

or:

ln(k1/k2) = (Ea/R)(1/T2 - 1/T1)

We can infer from the question that the milk sours 3 times as fast at the higher temperature (let's call it T1), so we can arbitrarily call k2 = 1 and k1 = 3.

a) Substitute:

ln(3) =  (Ea/R)(1/276.15 K - 1/293.15 K).

We get Ea/R = 5231.6. Multiply this by whatever value of R you choose to get Ea in your favorite energy unit. Remember the sig figs.

b) Again, let's let the lower temperature = T2, since we have defined k2 = 1:

ln(k1) = (5231.6)(1/276.15 K - 1/313.15);

ln(k1) = 2.24, so k1 = 9.38.

Since k2 corresponds to 64 hours, the time for the milk to sour at 40 C is 64 h / 9.38 = 6.8 hours.

What would have a higher boiling point water or hydrocarbon ( from penny liquid stacking)

Answers

Answer:

Im pretty sure its hydrocarbon

Explanation:

In the organization of living things, tissues combine to form

A)Cells

B)communities

C) organisms

D)Organs

Answers

Answer:

D

Explanation:

Answer:d

Explanation:

Which is the noble gas configuration for 31 Ga?

Answers

Answer:

1s22s22p63s23p63d104s24p1.

Explanation:

Gallium, Ga has 31 protons and 31 electrons.

Answer:

Ar 3d10 4s2 4p1

Explanation:

hope this serves you well!!

Write
the following separation techniques?
a. Filtration
b. Evaporation
C. Fractional distillation
d. Chromatography​

Answers

Answer:

Explanation: Fractional distillation

through which filter did water went through faster?​

Answers

Answer:

The filter that water went through faster is Filter paper

Which of these elements is the most ductile?
a. vanadium
b. mercury
c. germanium
d. astatine
e. xenon

Answers

Answer:

mercury

Explanation:

A different brand of iron tablet was analysed by Hitration with 0.0093 mol.L" potassium
dichromate via the reaction listed below;
Cr2O72- + 6Fe2+ + 14H+ + 2Cr3+ + 6Fe3+ + 7H20
In this experiment 4 tablets were crushed and dissolved in 200 cm3 of dilute acid. 25cm3
of this solution was used in the titration. The results of the titrations were as follows;
Titration Volume dichromate (cm)
1
33.0
2
32.05
3
32.15
4
32.10
Calculate the concentration of iron used in the titration (4 dp).
C1V1/C2V2 = n/n2

Answers

The concentration of iron used in the titration : 0.009 M

Further explanation

Given

Reaction

Cr₂O₇²⁻ + 6Fe²⁺ + 14H⁺ ⇒ 2Cr³⁺ + 6Fe³⁺ + 7H₂O

0.0093 mol/L potassium  dichromate

200 cm³ of dilute acid, 25cm³   was used in the titration.

Required

the concentration of iron

Solution

Titration formula

C₁V₁n₁=C₂V₂n₂⇒ From equation : n₁=6n₂(1=Cr₂O₇, 2=Fe)

titration average : 33+32.05+32.15+32.1 / 4 = 32.325 cm³(ml)

25 cm³ of iron solution used in titration :

[tex]\tt V_1=32.325~ml\\\\V_2=25~ml\\\\C_1=0.0093~M\\\\\\\\C_1.V_1.n_2=C_2.V_2.n_1\\\\0.0093\times 32.325\times 6=C_2\times 25\times 1\\\\C_2=0.07215~M[/tex]

Dilution(25 ml from 200 ml iron solution)

[tex]\tt C_2.V_2=C_1.V_1\\\\0.007215\times 25=C_1\times 200\\\\C_1=0.009~M[/tex]

What is the name of the compound with the formula LiNO3?

Answers

Answer:

Lithium nitrate

Explanation:

Lithium nitrate is an inorganic compound with the formula LiNO3. It is the lithium salt of nitric acid (an alkali metal nitrate).

ASAP PLZ HELP I WILL MARK BRAINLIEST Based on the diagram, what can you conclude about the pole of the magnet? O It is a south pole because the field lines spread out from this end. O It is a north pole because the field lines spread out from this end, O It is a south pole because the field lines enter the magnet at this end. O It is a north pole because the field lines enter the magnet at this end.​

Answers

Answer:C

Explanation:I took the test

Answer:

It is a south pole because the field lines enter the magnet at this end.

Explanation:

Find the volume of
this object.
5 cm
5 cm
5 cm
A
15 cm3
B
125 cm3
C
30 cm3

Answers

Answer:  B. [tex]125\ cm^3[/tex].

The volume of the given object = [tex]125\ cm^3[/tex]

Explanation:

Given : Dimensions of an object : 5 cm x 5 cm  x 5 cm [ it is a cube with all equal sides]

Formula to find the volume of a cube = [tex](side)^3[/tex]

[tex]=5^3\ cm^3=125\ cm^3[/tex]

Hence, the volume of the given object = [tex]125\ cm^3[/tex]

Therefore , the correct option is B. [tex]125\ cm^3[/tex].

How many grams of NaCl are needed to make 300ml of a 2% solution

Answers

Answer:

2grams as per the question

Which is larger: barium atom or a barium ion? Explain your answer in terms of atomic structure

Answers

Barium atoms are bigger as barium ion are cations meaning that lose electrons becoming over all more positive. Losing electrons decreases there radius or size
Barium atom is bigger than barium ion

Please help with this....thank you

Answers

Answer:

large cracks suddenly form

Explanation:

the tectonic plates begin to move causing cracks. I think

Please help, it’s much appreciated



If the hydrogen ion concentration,
[H+], in a solution is 2.65 x 10-2 M,
what is [OH-]?

Answers

Answer: acidic

Explanation:

Answer:

3.77 x 10^-13 M

Explanation:

What statements are always true about limiting reactants?
Select one or more:
1.The limiting reactant has a lower mass than other reactants.
2.The limiting reactant dictates the amount of product.
3.The limiting reactant is always the same for a given reaction.
4.There will be an excess of other reactants at the end of the reaction.
5.The limiting reactant is completely used up in the reaction.

Answers

Answer:

5.The limiting reactant is completely used up in the reaction

Explanation:

The limiting reactant is completely used up in the reaction is the correct answer because a limiting reactant is a reactant in chemical reaction that is completely consumed or used up in the chemical reaction. Limiting reactant when it is completely used up limits the amount of products that will be formed. The reaction will be halted or will stop when the limiting reactant is totally used up.

The statement that is right as regards a limiting reactants in a reaction is 5:.The limiting reactant is completely used up in the reaction.

The limiting reagent can be regarded as a reactant during  chemical reaction, which is been consumed totally at the end of the reaction without remains.

The amount of product that is   formed during a reaction can be limited by action of the limiting reagent this is because once this reagent is used up the reaction cannot proceed again.

Therefore, option 5, is correct.

Learn more at:https://brainly.com/question/19031443?referrer=searchResults

OTHER OPTIONS THAT COMPLETE THIS QUESTION ARE:

The limiting reactant has a lower mass than other reactants.

2.The limiting reactant dictates the amount of product.

3.The limiting reactant is always the same for a given reaction.

4.There will be an excess of other reactants at the end of the reaction.


A piece of dry ice at -76°C begins to sublimate (solid to
gas) when placed at the counter at room temperature. How
many bars are in the final phase energy (Eph)?

Answers

Answer:

D

Explanation:

4 bars

what's the formula for na and f , ca and br , mg and O ​

Answers

Answer:

NaF, CaBr2, MgO

Explanation:

Hi! For this problem, you are going to want to look at the charges of the elements in order to write their formulas.

NaF: Na has a charge of +1 and F has a charge of -1. This means that they have a 1:1 ratio and the formula is written as such - NaF.

CaBr2: Ca has a charge of +2 and Br has a charge of -1. For this problem you want to make sure that their formal charge (the charge of the entire molecule) equals 0. This means that the negative charges need to equal the positive charges. Looking at this, you are going to need to Br ions with a charge of -1 to equal one Ca ion with a charge of +2 - CaBr2.

MgO: Mg has a charge of +2 and O has a charge of -2. This means that they have a 2:2 ratio which simplifies to a 1:1 ratio and the formula is written as such - MgO.

Hope this helps!

Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:

(
)BaO2 + (
)H2SO4 → (
)H2O2 + (
)BaSO4

Answers

Answer:

1

1

1

1

Explanation:

the equation is balancing

A silver bar has a mass of 368g. What is the volume in cm³ of the bar? The density of silver is 19.5g/cm³.

Answers

Answer:

18.87 cm³

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

[tex]volume = \frac{mass}{density} \\[/tex]

From the question we have

[tex]volume = \frac{368}{19.5} \\ = 18.871794..[/tex]

We have the final answer as

18.87 cm³

Hope this helps you

Solve for x in the following equation?

v=w/x

Answers

Answer:

x = w/v

General Formulas and Concepts:

Pre-Algebra

Equality Properties

Explanation:

Step 1: Define

v = w/x

Step 2: Solve for x

Multiply x on both sides:                    xv = wDivide v on both sides:                      x = w/v

If I Gave A Pig Bacon Would He Eat It ?

Answers

probably, i wouldn’t do it, but like, if you find it necessary, go for it homeslice.

A common carboxylic acid used in cooking is acetic acid, if its composed of two carbons whats its iupac name

Answers

Answer:

ethane

Explanation:

Ethane is an organic chemical compound with chemical formula C ₂H ₆. At standard temperature and pressure, ethane is a colorless, odorless gas. Like many hydrocarbons, ethane is isolated on an industrial scale from natural gas and as a petrochemical by-product of petroleum refining

which is a way to express concentration of a solution? parts per billion moles molar mass force per square meter​

Answers

Answer:

parts per billion

Explanation:

I took the quiz

Answer:

parts per billion

Explanation:

edge 2021

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