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
Margaret [11]
3 years ago
5

Fluorine-18 is a radioactive isotope that decays by positron emission to form oxygen-18 with a half-life of 109.8 min. (A positr

on is a particle with the mass of an electron and a single unit of positive charge.) What is the rate constant (in min−1) for the decomposition of fluorine-18?
Chemistry
1 answer:
Lera25 [3.4K]3 years ago
6 0

Answer:

k = 6.31 x 10⁻³ min⁻¹

Explanation:

The equation required to solve this question is:

k = 0693 / t half-life

This equation is derived from the the equation from the radioctive first order reactions:

ln At/A₀ = -kt

where At is the number of isoopes after a time t , and A₀ is the number of of isotopes initially. The half-life is when the number of  isotopes has decayed by a half, so

ln(1/2) = -kt half-life

-0.693 = - k t half-life

t half-life = 109.8 min

⇒ k = 0.693 / t half-life = 0.693 / 109.8 min = 6.31 x 10⁻³ min⁻¹

You might be interested in
In a titration of 0.35 M HCl and 0.35 M NaOH, how much NaOH should be added to 45.0 ml of HCl to completely neutralize the acid?
Rom4ik [11]
<span>M(HCl) * </span><span>V(HCl) </span>= <span>M(NaOH) * </span><span>V(<span>NaO<span>H)
</span></span></span>
M(HCl) = 0.35
<span>V(HCl) = 45mL
</span>M(NaOH)= 0.35

now, solne for V(NaOH) by putting these values in the above equation.
M(HCl) * <span>V(HCl) </span>= <span>M(NaOH) * </span><span>V(NaOH)</span>

<span>0.35 * 45 = 0.35 * V(NaOH)</span>

<span>V(NaOH) = 45 mL</span>

8 0
3 years ago
Read 2 more answers
When taphonomy records show a short PMI and warm, humid conditions, the degree of certainty is probably _____.
puteri [66]

The degree of certainty is high.

7 0
4 years ago
Read 2 more answers
3. A light bulb containing argon gas is switched on,
Readme [11.4K]

Answer:

The assumption is quite reasonable.........

A lightbulb contains Ar gas at a temperature of 295K and at a pressure of 75kPa. The light bulb is switched on, and after 30 minutes its temperature is 418 K. What is a numerical setup for calculating the pressure of the gas inside the light bulb at 418K?

Explanation:

P

1

T

1

=

P

2

T

2

given constant

n

, and constant

V

, conditions that certainly obtain with a fixed volume light bulb.

And so

P

2

=

P

1

T

1

×

T

2

=

75

⋅

k

P

a

295

⋅

K

×

418

⋅

K

≅

100

⋅

k

P

a

.

Had the light bulb been sealed at normal pressure during its manufacture, what do you think might occur when it is operated?

5 0
2 years ago
Ethanol is added to gasoline because the oxygen it contains improves gasoline's burning efficiency. Its combustion reaction is g
ruslelena [56]

Answer:

A) The reaction is exothermic reaction

B) 46 gm CH3CH2OH  = 1236KJ

15.3 gm ch3ch2OH = 1236/46 x 15.3

= 411.10 KJ..........released

therefore  1 KJ = 0.239 K cal

so, 411.10 x 0.239 kcal

= 98.2529 .................. released

c) 54 gm of H2O produced = 1236KJ

so, 42.7 gm H2O produced = 1236/54 x 42.7KJ

= 977.35 KJ released.

Explanation:

7 0
3 years ago
The melting point of table salt is 801 degrees C. Is this a physical or chemical property?
wolverine [178]
Melting point is a physical property 
6 0
3 years ago
Read 2 more answers
Other questions:
  • Gastric juice in the stomach contains pepsin and sulfuric acid.<br><br><br> TrueFalse
    14·1 answer
  • What's the difference between saturated and unsaturated fatty acids?
    6·1 answer
  • How does an increase in volume affect equilibrium
    13·1 answer
  • The reaction 2a → a2​​​​​ was experimentally determined to be second order with a rate constant, k, equal to 0.0265 m–1min–1. if
    14·2 answers
  • What do the rows of the periodic table periodic table indicate
    10·1 answer
  • What is the freezing point (in degrees Celcius) of 4.14 kg of water if it contains 235.1 g of butanol, C 4 H 9 O H
    13·1 answer
  • Each side of a square is 8 by 10 metre find the area of the square​
    7·2 answers
  • mass of 2 * 10^21 number of atoms of an element is 0.4g. what is the mass of 0.5 mole of the element?​
    14·1 answer
  • How many grams calcium sulfite are in a 3.87 mole sample?
    6·1 answer
  • What is the maximum number of grams of copper that could be produced by the reaction of 30.0 of copper oxide with excess methane
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!