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
Elis [28]
3 years ago
6

A potassium-40 sample starts with 50 atoms, and 1.25 billion years later, there are 25 atoms. What is the half-life of potassium

-40?
A. 2.5 billion years
B. 25 years
C. 40 years
D. 1.25 billion years
Chemistry
1 answer:
guapka [62]3 years ago
5 0
D. 1.25 billion years
You might be interested in
Give the value of the quantum number ℓ, if one exists, for a hydrogen atom whose orbital angular momentum has a magnitude of 6√(
MakcuM [25]

Answer:

For this angular momentum, no quantum number exist

Explanation:

From the question we are told that

   The magnitude of the angular momentum is  L  = 6\sqrt{\frac{h}{2 \pi} }

The generally formula for Orbital angular momentum is mathematically represented as

           L  = \sqrt{(l * (l + 1)) } *  \frac{h}{2 \pi}

Where l is the quantum number

now  

We can look at the given angular momentum in this form as

      L  = 6\sqrt{\frac{h}{2 \pi} }    =  \sqrt{36}  * \sqrt{\frac{h}{2 \pi}} }

comparing this equation to the generally equation for Orbital angular momentum

     We see that there is no quantum number that would satisfy this equation

5 0
3 years ago
So I am lost and I don't know how what any of those conversion factor things are and I'm wondering how to do #2,3, and 4. (I did
dalvyx [7]

Explanation:

#2.

A centigram is 1/100 of a gram, so that means a gram equals 100 centigrams.

Therefore you multiply 72.4 grams by 100/1 (or just 100), and get 7240 cg.

You did that one right but put the wrong unit in the answer. It is is cg ( centigrams).

#3.

1 liter is equal to 1000 milliliters, and I kiloliter is equal to 1000 liters. So one kiloliter is 1000*1000 milliliters or 1,000,000 milliliters.

The conversion factor would be

1/1000000

#4.

1 gigabyte is equal to 10^9 bytes.

I byte is equal to 10^9 bytes.

So 1 gigabyte is 10^9 * 10^9 nanobytes, or 10^18.

The conversion factor would be (1*10^18)/1.

6 0
3 years ago
A student assisting with the experiment would observe all of the following about the electron transport chain EXCEPT:A. Electron
zheka24 [161]

Answer:

C. All electron carriers are mobile and hydrophobic

Explanation:

Hello,

In this case, it is widely known that the electron carriers move inside the inner mitochondrial membrane and consequently move electrons from one to another. In such a way, they are mobile, therefore they are largely hydrophobic as long as they are inside the membrane.

For instance, the cytochrome c is a water-soluble protein in a large range, therefore, the answer is: C. All electron carriers are mobile and hydrophobic.

Best regards.

5 0
4 years ago
What was one main point of Dalton's atomic theory?
sweet-ann [11.9K]

Answer:

C. That atoms made up the smallest form of matter

Explanation:

The crux of the Dalton's atomic theory is that atoms are the smallest form of matter. He propositioned that atoms is an indivisible particle and beyond an atom, no form of matter exists.

Series of discoveries through time have greatly shaped the Dalton's atomic theory. The discovery of cathode rays by J.J Thomson in 1897 opened up the atom. Atoms were now seen to be made up of some negatively charged particles. Ernest Rutherford through his gold foil experiment proposed the nuclear model of the atom.

4 0
3 years ago
Which answer is an isotope of 40/20x? <br><br> Question Pictured here:
Nesterboy [21]

An isotope of ₂₀⁴⁰X  ⇒₂₀⁴⁴X

<h3>Further explanation </h3>

The elements in nature have several types of isotopes

Isotopes are atoms that have the same number of protons and a different number of neutrons.

So Isotopes are elements that have the same Atomic Number (Proton)

In the following element notation,

\large {{{A} \atop {Z}} \right X}

X = symbol of elemental atom

A = mass number

  = number of protons + number of neutrons

Z = atomic number

   = number of protons = number of electrons, on neutral elements

For symbol of isotope X :

₂₀X⁴⁰ : atomic number = 20, mass number = 40

A. ₄₀²⁰X : atomic number = 40, mass number = 20, neutrons=20

B. ₂₀⁴⁰X²⁺ : atomic number = 20, mass number = 40, neutrons=20

C. ₂₁⁴⁰X : atomic number = 21, mass number = 40, neutrons=19

D. ₂₀⁴⁴X : atomic number = 20, mass number = 44, neutrons=22

7 0
3 years ago
Other questions:
  • Helpp need answer for a test
    15·1 answer
  • Which monkey fell of the bed
    6·2 answers
  • Physical and chemical properties, such as color, density, boiling point, solubility, conductivity, and flammability, A. do not d
    13·1 answer
  • In a laboratory, you scratch an unknown mineral on a piece of unglazed porcelain. Which property are you trying to determine?
    10·2 answers
  • As the mass number of the isotopes of hydrogen increases, the number of protons
    5·1 answer
  • A rectangular aquarium is 47.2 cm wide, 89 cm long, and 65.38 cm tall. What is the volume of the aquarium? How many liters of wa
    9·1 answer
  • If the solubility of a gas is 10.5 g/L at 650 kPa pressure, what is the solubility of the gas when the pressure is 200 kPa? Show
    5·1 answer
  • Cold packs, whose temperatures are lowered when ammonium nitrate dissolves in water, are carried by athletic trainers when trans
    6·1 answer
  • Picture of the question is below, if answered correctly, I will reward with brainliest.
    15·1 answer
  • Importancia de las disoluciones en la vida cotidiana
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!