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
LenaWriter [7]
2 years ago
10

You start out with 800 moles of a radioactive substance. After 24 hours, 100 moles remain. What is the half-life of the substanc

e in hours?
Question 1 options:

12 hours


4 hours


8 hours


6 hours
Chemistry
2 answers:
steposvetlana [31]2 years ago
7 0

Answer:

The correct answer would be 8 hours

Explanation:

Ludmilka [50]2 years ago
4 0

Answer:

12 hours

Explanation:

It would take 12 hours for half of the substance to remain

You might be interested in
A 46.9 gram sample of a substance has a volume of about 3.5 centimeters3. It is solid at a room temperature of 23ºC. Out of the
horrorfan [7]

Answer : (C) Hafnium is the most likely identity of the given substance.

Solution :  Given,

Mass of given substance (m) = 46.9 g

Volume of given substance (V) = 3.5 Cm^{3}

First, find the Density of given substance.

Formula used :    

Density=\frac{\text{Mass of given substance}}{\text{Voume of given substance}}

Now,put all the values in this formula, we get

Density=\frac{46.9 g}{3.5 Cm^{3} } = 13.4 g/Cm^{3}

So, we conclude that the density of given substance (13.4 g/Cm^{3}) is approximately equal to the density of Mercury and Hafnium (13.53 and 13.31 g/Cm^{3} respectively).

According to the question the substance is solid at room temperature but Mercury is liquid at room temperature. So, Mercury is not identical to the given substance.

Another element i.e, Hafnium is the element whose density is approximately equal to the given substance and also solid at room temperature. And we know that the melting point of solid is high.

So, Hafnium is the most likely element which is the identity of the given substance.

3 0
3 years ago
Read 2 more answers
What is the pH of a 0.050 M triethylamine, (C2H5)3N, solution? Kb for triethylamine is 5.3 ´ 10-4. Question options: 1) 11.69 2)
blsea [12.9K]
<span>the pH of a 0.050 M triethylamine, is 11.70
</span>
For triehtylamine, (C_{2}H_{5})_{3}N, the reaction will be
(C_{2}H_{5})_{3}N + H_{2}O ---\ \textgreater \ ( C_{2}H_{5})_{3}NH^{+} + OH^{-}

 and we know, pH = -log[H+] and pOH = -log[OH-]

Also, pOH + pH = 14

Now, the Kb value  = 5.3 x 10^-4

And kb =  \frac{( [( C_{2}H_{5})_{3}NH^{+} ]*  OH^{-} )}{[( C_{2}H_{5})_{3}N]}

 thus, [OH-] =(5.3 ^ 10-4) ^2 / 0.050

                    =0.00516 M 

Thus, pOH = 2.30 
 pH = 14 - pOH = 11.7
6 0
3 years ago
How does the urinary system maintain homeostasis?​
VladimirAG [237]

Answer:

here is ur ans Lilly

Explanation:

<h2>In addition to maintaining fluid homeostasis in the body, the urinary system controls red blood cell production by secreting the hormone erythropoietin. The urinary system also plays a role in maintaining normal blood pressure by secreting the enzyme renin.</h2>

hope it's helpful for you mark brainlest where you from , age

4 0
3 years ago
Read 2 more answers
Which of the following measurements is expressed to three significant figures?
Zepler [3.9K]
Which of the following measurements is expressed to three significant figures?
C. 5.60 km
Hope this helps!
5 0
3 years ago
Read 2 more answers
Ca(s)+2hno3(aq)→ca(no3)2(aq)+h2(g) identify the oxidizing agent.
aleksandr82 [10.1K]

To find for the oxidizing agent, first let us write the half reactions of this complete chemical reaction:

Ca = Ca2+ + 2e- <span>
2 H+ + 2e- = H2</span>

 

The oxidizing agent would be the substance of the element that is reduced. We know that an element is reduced when an electron is added to it. In this case, the element being reduced is H. Therefore the oxidizing agent is HNO3.

 

Answer:

<span>HNO3</span>

8 0
3 years ago
Read 2 more answers
Other questions:
  • How is the rate of appearance of h2o related to the rate of disappearance of o2?
    7·1 answer
  • The study of heat and heat changes is called:
    7·1 answer
  • The flame symbol represents which of the following hazards?
    8·2 answers
  • What happens when carbon dioxide at 74 c is placed in thermal contact with water at 14 c
    8·1 answer
  • The half life for the first order conversion of A to B is 56.6 hours. How long does it take for the concentration of A to decrea
    10·1 answer
  • Select the correct answer.<br> Which characteristic is a property of water?
    14·1 answer
  • WILL GIVE BRAINLIEST TO PERSON WHO ANSWERS FASTEST AND CORRECT BUT ANY ANSWERS TO JUST GET POINTS WILL GET REPORTED AND DELETED
    5·2 answers
  • In an atom how many protons and electrons
    12·2 answers
  • What is the average deer per month
    8·2 answers
  • Identify the limiting reactant when 9.65-g H2SO4 reacts with 6.10-g of NaOH.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!