Strontium atom loses 2 electrons to become an ion with 2 electrons lesser than its atom. Your answer is C.
<span>number of moles= mass / molecular mass
mass=131.50g
molecular mass of Zn(NO3)2 =189.39 g/mol
number of moles = 131.50 g/189.39 g/mol =0.69433 mol</span>
The number of moles that are contained in the given mass of propane (
is 1.7143 moles.
<u>Given the following data:</u>
- Mass of propane = 75.6 grams.
<u>Scientific data:</u>
- The molar mass of propane = 44.1 g/mol.
To calculate the number of moles that are contained in the given mass of propane ():
<h3>How to calculate the moles of a compound.</h3>
In this exercise, you're required to determine the number of moles of propane that are contained in the given sample:
Mathematically, the number of moles contained in a chemical compound is given by this formula:
Substituting the given parameters into the formula, we have;
Number of moles = 1.7143 moles.
Read more on number of moles here: brainly.com/question/3173452
Answer:<span>d. 145 minutes
</span>
Half-life is the time needed for a radioactive to decay half of its weight. The formula to find the half-life would be:
Nt= N0 (1/2)^ t/h
Nt= the final mass
N0= the initial mass
t= time passed
h= half-life
If 25.0% of the compound decomposes that means the final mass would be 75% of initial mass. Then the half-live for the compound would be:
Nt= N0 (1/2)^ t/h
75%= 100% * (1/2)^ (60min/h)
3/4= 1/2^(60min/h)
log2 3/4 = log2 1/2^(60min/h)
0.41503749928 = -60min/h
h= -60 min / 0.41503749928= 144.6min
