A radioactive sample has an activity of 450 cpm three half lives after the initial activity was determined. What was the original activity?

Answers

Answer 1

Answer:

original activity is 3600 cpm

Explanation:

3 half-lives = 450 cpm

2 half-lives = 900 cpm

1 half-life = 1800 cpm

answer = 3600 cpm


Related Questions

Inside a car that was at STP, a 1.33 L bottle warms up to 130 C. If the volume of the bottle remains constant, what is the pressure, in atm, inside the hot water bottle?

Answers

Answer:

[tex]P_2=1.48atm[/tex]

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to infer this problem is about the application of the Gay-Lussac's gas law to relate the initial and final pressure and temperature as shown below:

[tex]\frac{P_2}{T_2} =\frac{P_1}{T_1\\ }[/tex]

Thus, solving for the final pressure, P2, and using the temperatures in Kelvins, we obtain:

[tex]P_2 =\frac{P_1T_2}{T_1 }\\\\P_2 =\frac{1atm*403.15K}{273.15K}\\\\P_2=1.48atm[/tex]

Regards!

What is the total number of atoms in the formula
Ca(ClO3)2?

Answers

Answer:

9 atoms

Explanation:

Ca=1

Cl=2

O=6

add them all

answer

cl atom is 2

ca atom is 1

o atom is 6

why do tectonic plates move to form volcano

Answers

When the tectonic plates try to walk to burger king, they always bump into each other because of how close together they are. Once in a while, a tectonic plate will get so pis sed of, it will form a volcano to let out its anger.

What is the oxidation state of S in S032-?
Α. -8
Β. -2
C. +4.
D. +6

Answers

Answer:

A

Explanation:

I think that is the ans but am not sure

Water is said to be a good solvent for polar solutes because it has a negative end and a positive end. This explains why (IONIC/COVALENT) compounds dissolve easily in water. Highlight one​

Answers

yes thenpropert snd the negative end causes a iconic water fall

Which statement describes an Arrhenius acid

Answers

Answer:

According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs. Hence, the correct statement is arrhenius acid produces hydrogen ions in solution.

The temperature of a 95.4 g piece of copper decreases from 48°C to 25°C when the copper releases - 849 J of heat. What is the specific heat of copper?

Answers

This is my workings. Hope am correct

what is difference between pipette and flask

Answers

Answer:

Erlenmeyer flasks have a narrow neck over a conical base, while beakers are basically large open-mouthed glass jars with a lip and spout for pouring. Graduated cylinders are tall cylinders with a spout to pour liquids; they have hash marks on the side to measure the volume of their contents.

Explanation:

hope it helps you alot

Erlenmeyer flasks have a narrow neck over a conical base, while beakers are basically large open-mouthed glass jars with a lip and spout for pouring. Graduated cylinders are tall cylinders with a spout to pour liquids; they have hash marks on the side to measure the volume of their contents.

2.00 liters of gas at 1.00 atm and conpresssed it to a pressure of 6.00 atm, what would the volume of the gas be

Answers

Answer:

[tex]V_2=0.5L[/tex]

Explanation:

From the question we are told that:

initial Volume [tex]V_1=2.00L[/tex]

initial Pressure [tex]P_1=1 atm[/tex]

Final  Pressure [tex]P_2=6atm[/tex]

Generally the equation for Final Volume V_2 is mathematically given by

Since Boyle's law states

 [tex]P_1V_1=P_2V_2[/tex]

 [tex]V_2=\frac{P_1V_1}{P_2}[/tex]

 [tex]V_2=\frac{2*1}{6}[/tex]

 [tex]V_2=0.5L[/tex]

List some of the effects of the increased production of
greenhouse gases on the Earth​

Answers

Answer:

See Explanation

Explanation:

Green house gases are those gases believed to be responsible for the trapping of infrared ray close to the surface of the earth. The effect of the buildup of such gases include;

1) Rise in global temperature; Greenhouse gases trap infrared rays close to the surface of the earth there by leading to a continuous rise in the temperature of the earth. This is known as global warming.

2)Climate Change; Increase in the concentration of greenhouse gases in the atmosphere leads to different patterns of climatic events. This gradual change in the pattern of climatic events is called climate change.

3)Melting of polar ice caps and flooding; Increase in the concentration of greenhouse gases and consequent increase in the earth's temperature leads to the melting of polar ice caps and subsequently flooding in various parts of the world.

Pollution is any waste product that damages an ecosystem

True or false?

Answers

Answer:

True!

Explanation:

Not only products cause pollution, but the smoke from factories, the gas from our cars. Hope this is helpful! ^^

B. Hot water
The specific heat capacity of water is 4.186J/g °C
Calculate the temperature change when 8000 j of heat is added to 3g of water.
Use the equation q=mcAT
C. Specific heat capacity
Water has a specific heat capacity of 4.186J/g °C
Concrete has a specific heat capacity of 0.880 J/g °C
If a kg of water and a kg of concrete sit out in the sun on a hot day which one will have a change of temperature faster?

Explain why?

Answers

Answer:

The heat capacity measures the amount of heat necessary to raise the temperature of an object or system by one degree Celsius.

LEARNING OBJECTIVES

Explain the enthalpy in a system with constant volume and pressure

KEY TAKEAWAYS

Key Points

Heat capacity is the measurable physical quantity that characterizes the amount of heat required to change a substance’s temperature by a given amount. It is measured in joules per Kelvin and given by.

The heat capacity is an extensive property, scaling with the size of the system.

The heat capacity of most systems is not constant (though it can often be treated as such). It depends on the temperature, pressure, and volume of the system under consideration.

Key Terms

3x +14y=5xy
21y - x =2xy​

Answers

Answer:

456789

Explanation:

Determine if each of the following will form a neutral, acidic, or basic solution and explain why. Show your work.

a) NaHSO4

b) Na2SO4

c) NH4CN

Answers

Answer:

For a: The given salt is acidic in nature.

For b: The given salt is neutral in nature.

For c: The given salt is neutral in nature.

Explanation:

Salts are formed by the combination of an acid and a base. There are 3 types of salt:

Acidic salt: It is formed by the combination of strong acid and weak base.Basic salt: It is formed by the combination of a strong base and weak acid.Neutral salt: It is formed by the combination of strong acid and strong base or weak acid and weak base.

For the given options:

(a): [tex]NaHSO_4[/tex]

This salt is formed by the combination of sodium hydroxide (strong base)  and the partial dissociation of sulfuric acid (strong acid). It also has a replaceable hydrogen ion which can be produced when dissolved in water. Thus, the given salt is acidic in nature.

(b): [tex]Na_2SO_4[/tex]

This salt is formed by the combination of sodium hydroxide (strong base)  and sulfuric acid (strong acid).

Thus, the given salt is neutral in nature.

(c): [tex]NH_4CN[/tex]

This salt is formed by the combination of ammonium hydroxide (weak base)  and hydrocyanic acid (weak acid).

Thus, the given salt is neutral in nature.

HELP WITH FINAL CHEM

Answers

Answer:

idvd has a very high performance and a lot more than just the right side to get it all out

A car reaches 80 km/hr, then suddenly crashed into a concrete wall. Without a seat
belt, the crash test dummy slams into the car's dashboard because
A the crash test dummy's kinetic energy drops to zero
B the dashboard is pushed backwards into the crash test dummy
C the crash test dummy continues its motion until acted upon by an unbalanced
force
D Gravity is pulling the crash test dummy in the direction the car is moving

Answers

Answer:

C

Explanation:

inertia

inertia is the reluctance of an object at rest or moving to change its state of rest or motion

because the car was moving, the dummy moves with the speed of the car..so when the crash happened the dummy continued to move..it was feeling reluctant to come to rest so was moving

Balancee por tanteo las siguientes ecuaciones químicas. Escriba el nombre a reactantes y productos. H2O5 + H2O ---> HNO3 Na2O + OH2O --> ONaOH

Answers

Answer:

a. N₂O₅ + H₂O ⇒ 2 HNO₃ (pentóxido de dinitrógeno + agua ⇒ ácido nítrico)

b. Na₂O + H₂O ⇒ 2 NaOH (óxido de sodio + agua ⇒ hidróxido de sodio)

Explanation:

Tenemos que balancear, por el método de tanteo, las siguientes ecuaciones químicas.

a. En la primera reacción, el pentóxido de dinitrógeno reacciona con agua para formar ácido nítrico. Es una reacción de síntesis o combinación.

N₂O₅ + H₂O ⇒ HNO₃

Podremos obtener la ecuación balanceada si multiplicamos HNO₃ por 2.

N₂O₅ + H₂O ⇒ 2 HNO₃

b. En la segunda reacción, óxido de sodio reacciona con agua para formar hidróxido de sodio. Es una reacción de síntesis o combinación.

Na₂O + H₂O ⇒ NaOH

Podremos obtener la ecuación balanceada si multiplicamos NaOH por 2.

Na₂O + H₂O ⇒ 2 NaOH

T = 409.5 K, P = 1.50 atm: V = ?L

Answers

Explanation:

T = 409.5 K, P = 1.50 atm: V = 22.4 L The ideal gas law is: PV = nRT where. P = pressure. V = volume n = number of moles.

How different foods affect glucose levels in the body virtual lab.
Carry out the procedures outlined in the virtual lab. In your own words, summarize the steps you used to complete the virtual assignment. Explain what the test (independent) variable was, and what the outcome (dependent) variable was.
What is independent variable and dependent variable? In your own words.

Answers

Answer: this might have something to do with the pancreas

Explanation:

the pancreas produces insulin if subject a produces more insulin than subject b the reaction to the glucose will be different the pancreas breaks down the glucose into sugar and protiens hope this helps

Where to connect the lines? Pls answer

Answers

Answer: The given factors are matched to the effect it would have on the reaction rate are as follows.

Increase reaction rate

- Crushing the antacid tablet

- Using many antacid tables

- Adding a catalyst to the water

Decrease reaction rate

- Cooling the water during the reaction

No effect on reaction rate

- Adding food coloring to the water

Explanation:

When antacid tablet is crushed then there will be more number of particles available for reaction. Hence, more number of collisions will take place due to which rate of reaction increases.

Using many antacid tables will also increase the number of molecules due to which there will be more collisions. Hence, more will be it's rate of reaction.

A catalyst is defined as a substance which helps in increasing the rate of a reaction without itself getting consumed in the reaction.

Therefore, adding catalyst to the water will also increase the rate of reaction.

When water is cooled during the reaction then kinetic energy between molecules decreases due to which there will be less number of collisions. Hence, rate of reaction will decrease.

Adding food coloring will have no effect on the rate of reaction as it is only changing the color of solution and does not participate in the chemical reaction.

Thus, we can conclude that given factors are matched to the effect it would have on the reaction rate are as follows.

Increase reaction rate

- Crushing the antacid tablet

- Using many antacid tables

- Adding a catalyst to the water

Decrease reaction rate

- Cooling the water during the reaction

No effect on reaction rate

- Adding food coloring to the water

If 4.03 x 102 mL of water vapor is at STP, then determine the mass, in grams, of the water vapor. Round your
answer to three significant figures.

Answers

Answer:

you me me

Explanation:

got me me

A seais usually defined as A.A body of freshwater that is not connected to the ocean B. A body of freshwater that is connected to the ocean C. A body of salt water that is not connected to the ocean D. Body of salt water that is connected to the ocean

Answers

Answer:

D. Body of salt water that is connected to the ocean

Explanation:

An ocean is a body of salt water which covers approximately 70% of the Earth's surface. About 97% of the Earth's water is comprised of ocean and as such it is the most prominent and defined feature of the Earth. There are basically four (4) categories of an oceanic basin and these are;

1. The Pacific ocean.

2. The Artic ocean.

3. The Atlantic ocean.

4. The Indian ocean.

A sea is usually defined as a body of salt water that is connected to the ocean and are surrounded (enclosed) by land partially.

Basically, a sea is formed where a land and an ocean meet and as a result, an ocean is usually bigger than a sea.

Some examples of seas around the world are Red sea, Mediterranean sea, Sargasso sea, Caribbean sea, Baltic sea, Caspian sea, Chuckchi sea, etc.

Answer:

Yes The Anwer is D Hope This Help:)

what is the first 30 elements in chemistry​

Answers

Answer:

Hydrogen (H)

Helium (He)

Lithium (Li)

Beryllium (Be)

Boron (B)

Carbon (C)

Nitrogen (N)

Oxygen (O)

Explanation:

that's the main ones I know

Answer:

H,He,Li,Be,B,C,N,O,F,Ne,Na,Mg,Al,Si,P,S,Cl,Ar,K,Ca,Sc,Ti,V,Cr,Mn,Fe,Co,Ni,Cu,Zn...

Explanation:

H stands for hydrogen

He stands for helium

Li stands for lithium

Be stands for beryllium

B stands for boron

C stands for carbon

N stands for nitrogen

O stands for oxygen

F stands for fluorine

Ne stands for neon

Na stands for sodium

Mg stands for magnesium

Al stands for aluminum

Si stands for silicon

P stands for phosphorus

S stands for sulfur

Cl stands for chlorine

Ar stands for argon

K stands for potassium

Ca stands for calcium

Sc stands for scandium

Ti stands for titanium

V stands for vanadium

Cr stands for chromium

Mn stands for manganese

Fe stands for iron

Co stands for cobalt

Ni stands for nickel

Cu stands for copper &

Zn stands for zinc

HOPE THIS ANSWER WILL HELP YOU!!!

Are bonds ever truly 100 % ionic or 100 % covalent and why?

Answers

No compound is 100% ionic. If the bond involves the same atoms (a homonuclear bond, A-A) then the bond must be 100% covalent because neither atom has the ability to attract the electron pair more strongly than the other. ... The reason for this is that an electron is never completely transferred from one atom to another.

what is the total number of protons in carbonate, CO2/3- please help

Answers

Answer:

30 positive charged protons

Can anyone please suggest me a good and easy project topic for physics and chemistry. For class nine or ten students.Please please please help me.​

Answers

Volcano , bleach and fabuloso , flour and soap

An experiment requires a solution of 60 % ethanol by volume. What volume of alcohol should be added to make a 200 mL of this solution?​

Answers

Answer: 120 mL of ethanol must be added.

Explanation:

We are given:

60% ethanol by volume

This means that 60 mL of ethanol is present in 100 mL of solution

Given volume of solution = 200 mL

Applying unitary method:

If 100 mL of solution contains 60 mL of ethanol

So, 200 mL of solution will contain = [tex]\frac{60}{100}\times 200=120mL[/tex] of ethanol

Hence, 120 mL of ethanol must be added.

Solve the given problems showing all work for each. 1. Calculate the molar mass/formula mass of ammonium sulfate -- (NH4)2SO4 , The atomic mass of Nitrogen (N) = 14.0, Sulfur (S) = 32.1, Hydrogen (H) = 1.0, & Oxygen (O) = 16.0 *

Answers

Answer:

The molar mass of ammonium sulfate, (NH₄)₂SO₄ = 132.1 g

Explanation:

The molar mass of a compound is the mass of 1 mole of the given substance.

For a compound the molar mass of the compound is obtained by summing the product of the number of atoms and the atomic masses of the atoms present in the compound.

To calculate the molar mass of ammonium sulfate, (NH₄)₂SO₄:

Atomic masses of the elements are as follows; Nitrogen (N) = 14.0, Sulfur (S) = 32.1, Hydrogen (H) = 1.0, & Oxygen (O) = 16.0

Mass of Nitrogen present = 14.0 × 2 = 28.0 g

Mass of hydrogen present = 1.0 × 4 × 2 = 8.0 g

Mass of sulfur present = 32.1 × 1 = 32.1 g

Mass of oxygen present = 16.0 × 4 = 64.0 g

Molar mass of ammonium sulfate, (NH₄)₂SO₄ = (28.0 + 8.0 + 32.1 + 64.0) g = 132.1 g

Therefore, the molar mass of ammonium sulfate, (NH₄)₂SO₄ = 132.1 g

Which are characteristics of electromagnetic waves? Check all that apply.

Answers

Where is the question or link

Answer:

Electromagnetic waves are typically described by any of the following three physical properties: frequency (f), wavelength (λ), or intensity (I). Light quanta are typically described by frequency (f), wavelength (λ), or photon energy (E). The spectrum can be ordered according to frequency or wavelength.

Match each element or compound with the appropriate symbol or molecular formula. Carbon dioxide CO2 carbon o oxygen Н H water с hydrogen H2O

Answers

Answer:

Carbon dioxide ---> CO₂

Water ----> H₂O

Carbon ---> C

Oxygen ----> O₂

Hydrogen ----> H₂

Explanation:

The molecular formula of an element or compound is a formula which represents the composition of a molecule of that element or compound. It consists of the formula representing the atoms present as well as the number of atoms of each element innthe compound written as subscript innthe formula of the element or compound.

The molecular formula of the given elements and compounds are given below:

Carbon dioxide ---> CO₂

Water ----> H₂O

Carbon ---> C

Oxygen ----> O₂

Hydrogen ----> H₂

The molecular formula of carbon dioxide shows that in a molecule of carbon dioxide, there are two atoms of oxygen and one atom of carbon present in a molecule of carbon dioxide.

The molecular formula of water shows that are two atoms of hydrogen and one atom of oxygen present in a molecule of water.

The molecular formula of carbon shows that there are one carbon atoms in a molecule of carbon.

The molecular formula of oxygen shows that there are two oxygen atoms in a molecule of oxygen gas.

The molecular formula of hydrogen shows that there are two molecules of hydrogen in a molecule of hydrogen gas.

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