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
Iteru [2.4K]
3 years ago
6

Lt takes 4 hr 39 min for a 2.00-mg sample of radium-230 to decay to 0.25 mg. what is the half-life of radium-230?

Chemistry
1 answer:
Rufina [12.5K]3 years ago
6 0
Radioactive decay => C = Co { e ^ (- kt) |

Data:

Co = 2.00 mg
C = 0.25 mg
t = 4 hr 39 min

Time conversion: 4 hr 39 min = 4.65 hr

1) Replace the data in the equation to find k

C = Co { e ^ (-kt) } => C / Co = e ^ (-kt) => -kt = ln { C / Co} => kt = ln {Co / C}

=> k = ln {Co / C} / t =  ln {2.00mg / 0.25mg} / 4.65 hr = 0.44719

2) Use C / Co  = 1/2 to find the hallf-life

C / Co = e ^ (-kt) => -kt = ln (C / Co)

=> -kt = ln (1/2) => kt = ln(2) => t = ln (2) / k

t = ln(2) / 0.44719 = 1.55 hr.

Answer: 1.55 hr
You might be interested in
How much work (in J) is involved in a chemical reaction if the volume decreases from 4.35 to 1.20 L against a constant pressure
Marianna [84]

Answer:

W = -262 J.

Explanation:

Hello there!

In this case, according to the given information, we can recall the definition of work in terms of constant pressure and variable volume as follows:

W=P(V_2-V_1)

So we plug in the given pressure and volumes to obtain:

W=0.822atm(1.20L-4.35L)\\\\W=-2.60atm*L

Now, we convert this number to J (Pa*m³) by using the shown below conversion factor:

W=-2.60atm*L*\frac{101325Pa}{1atm} *\frac{1m^3}{1000L}\\\\W=-262J

Regards!

3 0
3 years ago
Give TWO examples of energy conversion that produces unwanted forms of energy.
34kurt

For example, consider the energy used by an electric fan. The amount of electrical energy used is greater than the kinetic energy of the moving fan blades. Because energy is always conserved, some of the electrical energy flowing into the fan's motor is obviously changed into unusable or unwanted forms.

8 0
2 years ago
Historically the troubadour was a ____.
eimsori [14]

Composer and performer of Old Occitan lyric poetryduring the High Middle Ages (1100–1350). Since the word troubadour is etymologically masculine, a female troubadour is usually called a trobairitz.


6 0
3 years ago
What are the similarities and differences between protons and neutrons
storchak [24]

"Electric charge: the proton and electron are electrically charged, while the neutron is not. The proton and electron, however, are oppositely charged. Role in the atom: Protons and neutrons are closely bound together in the nucleus of an atom, while electrons are spread out around the nucleus."

8 0
3 years ago
The product of nuclear ___ is several nuclei
garri49 [273]

I think Its "fission"

3 0
3 years ago
Other questions:
  • For the following scenarios what is the metal? A piece of metal weighing 59.047 g was heated to 100.0 degree C and then put it i
    10·1 answer
  • An anode is an electrode immersed in the half-cell where _____ takes place.
    5·2 answers
  • Who developed a way of showing valence electrons?
    6·2 answers
  • DNA samples should not be stored where?
    10·2 answers
  • The population of the world nearly doubled between the years of 1965 and 2000.
    13·1 answer
  • A scientist measured an increase in nitrous oxide in the atmosphere. This increase would result in
    7·2 answers
  • List two processes from which it may be concluded that the particles of a gas move continuously.
    13·1 answer
  • Please help!!!!!!!!!!!!!!
    14·1 answer
  • 2. The electrons in a bond between 2 Iodine atoms are shared
    10·1 answer
  • Which of the following best describe the chronological way of specimen preparation?
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!