526 L O2 x 1 mol O2 / 22.4 L = 23.5 mol O2
Half-life is the length of time it takes for half of the radioactive atoms of a specific radionuclide to decay. A good rule of thumb is that, after seven half-lives, you will have less than one percent of the original amount of radiation.
<h3>What do you mean by half-life?</h3>
half-life, in radioactivity, the interval of time required for one-half of the atomic nuclei of a radioactive sample to decay (change spontaneously into other nuclear species by emitting particles and energy), or, equivalently, the time interval required for the number of disintegrations per second of a radioactive.
<h3>What affects the half-life of an isotope?</h3>
Since the chemical bonding between atoms involves the deformation of atomic electron wavefunctions, the radioactive half-life of an atom can depend on how it is bonded to other atoms. Simply by changing the neighboring atoms that are bonded to a radioactive isotope, we can change its half-life.
Learn more about half life of an isotope here:
<h3>
brainly.com/question/13979590</h3><h3 /><h3>#SPJ4</h3>
Answer:
c. Cr
Explanation:

The compound is containing
ion.
If acid reacts with it, CO_2 evolves.

therefore, Cr would form a precipitate when added to an aqueous solution of this compound. Cr2CO3 is the precipitate.
Answer:
4.16g of MgCl2
Explanation:
First, let us generate a balanced equation for the reaction:
Mg + 2HCl —> MgCl2 + H2
Molar Mass of Mg = 24g/mol
Molar Mass of MgCl2 = 24 + (2x35.5) = 24 + 71 = 95g
From the equation,
24g of Mg produced 95g of MgCl2.
Therefore, 1.05g of Mg will produce = (1.05x95)/24 = 4.16g of MgCl2