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
rusak2 [61]
3 years ago
9

Iodine-131 decays with a half-life of 8.02

Chemistry
1 answer:
dlinn [17]3 years ago
3 0
Radioactive material undergoes 1st order decay kinetics.

For 1st order decay, half life = 0.693/k

where k = rate constant

k = 0.693/half life = 0.693/8.02 = 0.0864 day-1

Now, for 1st order reaction,
k = \frac{2.303}{t} X log \frac{initial.conc}{final.conc}

Given: t = 6.01d, initial conc. = 5mg

∴0.0864 = \frac{2.303}{6.01} X log \frac{5}{final.conc}
∴ final conc. = 2.975 mg
You might be interested in
Which statement correctly describes potassium iodide, KI? There is a one-to-one ratio of potassium ions to iodide ions. Potassiu
elena-14-01-66 [18.8K]

The answer is there is a one-to-one ratio of potassium ions to iodide ions.

Explanation :

- (K) belongs to Alkali metals in group (1A) that contains (1) electron in the outermost energy level, whereas, (I) is from halogens in group (7A) that contains (7) electron in the outermost energy level.

- To achieve stability, both atoms tend to reach the nearest noble state (outermost level occupies 8 electrons). Therefore, (K) loses its outer electron and gives it to (I) which now has a completely filled outer level and an ionic bond is formed between the two.

- The valency (number of electrons lost, gained or shared) of both atoms is equal ”monovalent” which means one-to-one ratio..


5 0
3 years ago
Read 2 more answers
Which fact below is describing a base?
QveST [7]
7<span> to 49 10 to 100. 30 Secs. 3. What is the </span>pH<span> value of pure </span>water<span>? 0 3 </span>7<span> 10 ... How do acids </span>taste<span>? </span>bitter sour<span> sweet salty. 30 Secs. </span>7<span>. How do </span>bases taste<span>? </span>bitter<span> ... 8. Which kind of solution would react with a metal? acidic basic </span>neutral water<span> ... cocoa </span>has<span> a </span>bitter taste<span>. It is most likely which of the following? acid </span><span>base neutral</span>
6 0
3 years ago
With white light, a team measured a 0.7% percent change with 3.5g of plant matter in a one liter container. Convert
Strike441 [17]

moles CO₂ = 5.57.10⁻⁴

<h3>Further explanation   </h3>

A mole is a number of particles(atoms, molecules, ions)  in a substance

Can be formulated :

\tt mol=\dfrac{mass}{MW}

0.7% percent change with 3.5g of plant matter

mass :

\tt 0.7\%\times 3.5~g=0.0245~g

moles :

\tt moles=\dfrac{0.0245}{44}=0.000557=5.57.10^{-4}

5 0
3 years ago
What is the percent composition of hydrogen in NH4HCO3?
Readme [11.4K]
To find the Percent Composition of an atom, you use this formula:
Mass of element in the compound you're studying on ( in this case it's 5 since there is 5 Hydrogens) over the mass of the compound (which is here 79), Multiplied by 100 since you want a percent. 
So we get: 
\frac{5}{79} * 100
So you get about: 
0.063 * 100
6.3

So, the percent composition of Hydrogen in NH4HCO3 is 6.3%

Hope this Helps! :D


7 0
3 years ago
Read 2 more answers
T/F___ At the eutectic composition, an alloy can solidify at a constant temperature.___ For effective dispersion strengthening,
azamat

Answer:

  • TRUE
  • FALSE
  • TRUE
  • FALSE
  • FALSE
  • TRUE

Explanation:

  • At the eutectic composition, an alloy can solidify at a constant temperature : TRUE . this is because at eutectic composition the type of reaction that takes place there is invariant reaction in its thermal equilibrium
  • For effective dispersion strengthening, the dispersed phase should be needle-like, as opposed to round : FALSE. because the rounded shape will not cause a crack.
  • Intermetallic compounds are usually hard and brittle : TRUE. because Intermetallic compounds prevents dislocation movements and this makes them brittle and hard
  • For the effective dispersion and strengthening, the dispersed phase should be continuous : FALSE. this is because the dispersed precipitate must be small and not continuous
  • Stoichiometric intermetallic compounds exist over a range of compositions : FALSE
  • Faster solidification results in smaller interlamellar spacing : TRUE
4 0
3 years ago
Other questions:
  • Choose the statement that correctly describes the diagram. A. Side B has a higher concentration of particles than side A. B. The
    12·2 answers
  • Given the chemical equation, predict the ΔS system for this change.
    6·1 answer
  • Why does it take longer to boil water then melt ice?
    9·1 answer
  • What type of forces occur at convergent boundaries?
    10·1 answer
  • ¿por qué entre el calcio (Ca) que pertenece al segundo grupo y el galio (Ga) que pertenece al tercer grupo hay 10 elementos, ¿Qu
    12·1 answer
  • Putting rock salt on the roads during a snowstorm is an example of
    9·2 answers
  • What volume of carbon dioxide can be produced from the combustion of 2.0 L of methane at STP?
    12·1 answer
  • How many atoms does theobromine have
    13·1 answer
  • Why are properties of covalent compounds so diverse
    6·1 answer
  • 300g de acido comercial se disuelve en agua destilada contenidos en un cono, cuyo radio es de 0.005Km y 300cm de altura, si la d
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!