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
KonstantinChe [14]
3 years ago
12

Which phrase describes the decay modes and the half-lives of K-37 and K-42?

Chemistry
2 answers:
True [87]3 years ago
7 0
Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.

Among the choices the phrase describes the decay modes and the half-lives of K-37 and K-42 is different decay modes and different half-lives 
andrew11 [14]3 years ago
6 0

Answer: (3) different decay modes and different half-lives

Explanation: Potassium-37 and Potassium-42 have the same number of protons  but different numbers of neutrons i.e. they have same atomic number but different mass number. They are isotopes. Thus K-37 and K-42 have different decay modes

K-37 is positron decay and K-42 is beta decay.

_{19}^{37}{\textrm {Kr}}\rightarrow _{18}^{37}{\textrm {Ar}}+_{+1}^0{\textrm {e}}

_{19}^{42}{\textrm {Kr}}\rightarrow _{20}^{42}{\textrm {Ca}}+_{-1}^0{\textrm {e}}


K-37 has a half life of 1.23 seconds and K-42 has a half life of 12.4 hrs.

Thus they have different decay modes and different half lives.

You might be interested in
The chemical formula for magnesium oxide is MgO. A chemist determined by measurements that 0.030 moles of magnesium oxide partic
tamaranim1 [39]

Answer:

1.209g of MgO participates

Explanation:

In this problem, we have 0.030 moles of MgO that participates in a particular reaction.

And we are asked to solve for the mass of MgO that participates, that means, we need to convert moles to grams.

To convert moles to grams we need to use molar mass of the compound:

<em>1 atom of Mg has a molar mass of 24.3g/mol</em>

<em>1 atom of O has a molar mass of 16g/mol</em>

<em />

That means molar mass of MgO is 24.3g/mol + 16g/mol = 40.3g/mol

And mass of 0.030 moles of MgO is:

0.030 moles MgO * (40.3g/mol) =

<h3>1.209g of MgO participates</h3>
3 0
2 years ago
PLZ HELP!!!!!!!!!!!!!
gregori [183]

117.22 g are needed to react with an excess of Fe2O3 to produce 156.2 g of Fe.

Explanation:

                  Moles of Fe = Mass of Fe in grams / Atomic weight of Fe

                                        = 156.2 / 55.847

                  Moles of Fe  = 2.79.

The ratio between CO and Fe id 3 : 2.

                  Moles CO needed  = 2.79 * (3 / 2)

                                                   = 4.185.

 To calculate Atomic weight of CO,

                  Atomic weight of carbon = 12.011

                  Atomic weight of oxygen= 15.9994

        Atomic weight of CO = 12.011 + 15.9994 = 28.01 g / mol.

                 Mass of CO   = 4.185 * 28.01 = 117.22 g.      

5 0
3 years ago
What is exothermic and endothermic? How do they differ?
BabaBlast [244]
Exothermic  releases energy(heat) from the system to the surrounding
endothermic takes energy (heat) from the surrounding to the system
6 0
3 years ago
Which of the following results in a chemical change in matter?
LenKa [72]
The correct answer is 

D burning wood

because it's changing the wood.

The other's are physical changes because it's still the same thing, it's just in a different form.

Glad I could help, and good luck!

AnonymousGiantsFan
8 0
3 years ago
If a sound wave speeds up and its frequency does not change, what happens to the wavelength?
yan [13]

Answer: No, the speed of propagation is constant in a given medium; only the wavelength changes as the frequency changes.

Explanation:

5 0
2 years ago
Other questions:
  • How many molecules of sulfur trioxide would react with 68.9 L of water at STP to produce sulfuric acid? SO3 + H2O H2(SO4)
    11·1 answer
  • Organic compounds are distinguished by molecules that contain ________ bonded to other elements.
    14·1 answer
  • Which molecule listed below is a nonpolar molecule?
    12·1 answer
  • What effect does carbon dioxide have on tap water ​
    11·2 answers
  • At which temperature would a can of soda be most fizzy when it is opened?
    13·2 answers
  • a 10.99g sample of NaBr contains 22.34% Na by mass. Considering the law of constant composition (define proportions), how many g
    10·1 answer
  • Find molar mass of a gas when the density is given as 1.25g / L
    11·1 answer
  • I will give 15 points
    15·2 answers
  • Who knows any four object in which all three States of matter co-exist​
    15·2 answers
  • In which of these situations should a fire blanket be used?
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!