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GrogVix [38]
3 years ago
10

Isotope b has a half-life of 3 days. a scientist measures out 100 grams of this substance. after 6 days has passed, the scientis

t reexamines the sample.
Chemistry
1 answer:
Brilliant_brown [7]3 years ago
6 0
So half life is the time taken for a sample to decay to half its original mass, its a constant and applies to any original mass, it could be 5g or 1kg, it will take the same amount of time for the original mass to half. In this case the half life is 3 days.

After 3 days the sample will be at half its original mass, now 50g. 

Now we can treat the 50g as if its a new sample. After another 3 days (6 days in total) there will be half of 50g left, = 25g. 


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Answer:the number of moles represented by 3.0 x 10^24 atoms of Ag is 0.500mol 0.500 m o l .

Explanation:

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You know that 8.9 moles of solute particles are dissolved in that liquid solution. If the molarity of the solution is 25 M, how
pychu [463]

Answer:

V = 0.356 L

Explanation:

In this case, we need to use the following expression:

M = n/V (1)

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M: molarity of solution (mol/L or M)

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Now, replacing the given data we can solve V:

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5 0
3 years ago
Hiii pls help me to write out the ionic equation ​
emmasim [6.3K]

Answer:

<u>STEP I</u>

This is the balanced equation for the given reaction:-

2KOH_{(aq)} + H_2SO_4{}_{(aq)}   \rightarrow K_2SO_4{}_{(aq)} + 2H_2O_{(l)}

<u>STEP II</u>

The compounds marked with (aq) are soluble ionic compounds. They must be

broken into their respective ions.

see, in the equation KOH, H2SO4, and K2SO4 are marked with (aq).

On breaking them into their respective ions :-

  • 2KOH -> 2K+ + 2OH-
  • H2SO4 -> 2H+ + (SO4)2-
  • K2SO4 -> 2K+ + (SO4)2-

<u>STEP III</u>

Rewriting these in the form of equation

\underline{\pmb{2K^+} }+ 2OH^- + 2H^+ + \pmb{\underline{{SO_4{}^{2-}}} \: \rightarrow \:  \underline{\pmb{2K^+}}} + \underline{\pmb{SO_4{}^{2-}}} + 2H_2O

<u>STEP </u><u>IV</u>

Canceling spectator ions, the ions that appear the same on either side of the equation

<em>(note: in the above step the ions in bold have gotten canceled.)</em>

\boxed{ \mathfrak{ \red{ 2OH^-{}_{(aq)} + 2H^+{(aq.)} \rightarrow H_2O{}_{(l)}}}}

This is the net ionic equation.

____________________________

\\

\mathfrak{\underline{\green{ Why\: KOH \:has\:  been\: taken\: as\: aqueous ?}}}

  • KOH has been taken as aqueous because the question informs us that we have a solution of KOH. by solution it means that KOH has been dissolved in water before use.

[Alkali metal hydroxides are the only halides soluble in water ]

4 0
3 years ago
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Answer:

B 1.23 g/cc

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C. 0.23 g/cc
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D. 4.14 g/cc
This is much greater than 1.03 g/cc and the result would be sinking.
5 0
3 years ago
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