1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
aivan3 [116]
3 years ago
6

A radioactive substance used in nuclear weapons decays at the rate of 3.33.3​% per year. calculate the​ half-life of the radioac

tive substance.
Chemistry
1 answer:
mylen [45]3 years ago
3 0
The amount of substance that is present after t years given that the half-life of the substance is h is calculated through the equation,

   A(t) = A(o)(0.5^t/h)

If after a year, the rate of decay is equal to 33.3% then,

   A(t)/A(o) = (1/3) = 0.5^(1/h)

The value of h from the equation is 0.63 years. 

Answer: 0.63 years
You might be interested in
When you walk, you push against the floor, and _________.
Taya2010 [7]
When you walk, you push against the floor, and t<span>he floor pushes back against you.

Answer: B. The floor pushes back agaisnt you. 

Good luck with your studies, I hope this helps~!
</span>
7 0
3 years ago
Please help with chemistry question... It would help me tremendously and if you can, please show work :)?
Alexxandr [17]

Answer:

5.06 atm

Explanation:

Step 1:

Data obtained from the question. This includes:

Mass of S2O = 175g

Volume (V) = 16600 mL

Temperature (T) = 195°C

Pressure (P)

Step 2:

Determination of the number of mole of S2O in 175g of S2O.

Mass of S2O = 175g

Molar Mass of S2O = (32x2) + 16 = 64 + 16 = 80g/mol

Number of mole of S2O =.?

Number of mole = Mass/Molar Mass

Number of mole of S2O = 175/80

Number of mole of S2O = 2.1875 moles

Step 3:

Conversion to appropriate units.

It is essential to always express the various variables in the right units of measurement in order to obtain the desired answer in the right units.

For volume:

1000mL = 1L

Therefore, 16600mL = 16600/1000 = 16.6L

For temperature:

Temperature (Kelvin) = temperature (celsius) + 273

Temperature (celsius) = 195°C

Temperature (Kelvin) = 195°C + 273 = 468K

Step 4:

Determination of the pressure.

The pressure can be obtained by the application of the ideal gas equation. This is illustrated below:

Volume (V) = 16.6L

Temperature (T) = 468K

Number of mole (n) = 2.1875 moles

Gas constant (R) = 0.082atm.L/Kmol

Pressure (P) =

PV = nRT

P x 16.6 = 2.1875 x 0.082 x 468

Divide both side by 16.6

P = (2.1875 x 0.082 x 468) /16.6

P = 5.06 atm

Therefore, the pressure is 5.06 atm

6 0
3 years ago
The standard enthalpy of formation of Ca2+ (g) (∆H = 1934 kJ/mol)
Alex73 [517]

Answer:

see explanation

Explanation:

The process of ionization to produce cations is endothermic. For formation of Ca⁺² two ionization steps need be illustrated as follows...

1st ionization step: Ca° + 590Kj => Ca⁺ + e⁻

2nd ionization step: Ca⁺ + 1151Kj => Ca⁺² + e⁻

__________________________________-

Net Ionization Rxn: Ca° + 1741Kj => Ca⁺² + 2e⁻

6 0
3 years ago
For the reaction at 298 K, 2NO2(g) N2O4(g) the values of ΔH° and ΔS° are -58.03 kJ and -176.6 J/K, respectively. Calculate the v
Ierofanga [76]

Answer:

\Delta G^o=-5.4032 kJ

The temperature for \Delta G^o=0[/tex is [tex]T=328.6 K

Explanation:

The three thermodinamic properties (enthalpy, entropy and Gibbs's energy) are linked in the following formula:

\Delta G^o=\Delta H^o + T*\Delta S^o

Where:

\Delta G^o is Gibbs's energy in kJ

\Delta H^o is the enthalpy in kJ

\Delta S^o is the entropy in kJ/K

T is the temperature in K

Solving:

\Delta G^o=-58.03 kJ - 298K*-0.1766 kJ/K

\Delta G^o=-5.4032 kJ

For \Delta G^o=0:

0=\Delta H^o - T*\Delta S^o

\Delta H^o= T*\Delta S^o

T=\frac{\Delta H^o}{\Delta S^o}

T=\frac{-58.03 kJ}{-0.1766 kJ/K}

T=328.6 K

3 0
3 years ago
Read 2 more answers
In the electrolysis of molten libr, which product forms at the cathode?
Ira Lisetskai [31]
Sodium metal forms at the cathode
6 0
3 years ago
Other questions:
  • Definition of sound waves
    13·1 answer
  • If you want to produce 6.2 moles nacl, how many moles of na will you need if you have excess cl2
    11·1 answer
  • It is best to say that electric motors require _______ to work. a. a continuous current b. a galvonometer c. a generator d. ener
    13·1 answer
  • A) 5 days<br><br> b) 8 days<br><br> c) 9 days. i’m thinking maybe c <br><br> d) 11 days
    10·2 answers
  • 5. What is the molar mass of ethanol (C2H5OH)?
    6·1 answer
  • Law of electrolysis was given by<br>a.lamark. b.Ostwald<br>c.Faraday. d.Arrhenius<br>​
    7·1 answer
  • What are some ways the stars in the photo could be grouped or classified
    13·1 answer
  • Quick question: are ionic compounds solid AND aqueous at room temperature. Or just solid at room temperature.
    9·2 answers
  • A children's liquid medicine contains 100 mg of the active ingredient in 5 mL. If a child should receive 150 mg of the active in
    15·1 answer
  • What is the coordination number for atoms that pack within the diamond cubic crystal structure?.
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!