Answer:
Two Half-lives
Explanation:
Let number of Parent nuclei Initially present be X,
Then, finally 
Parent nuclei Will remain with 
daughter nuclei.
In one half- life , parent nuclei becomes half of initial.
So, starting with X parent nuclei,
After one half-life, it will degrade to 
.
After another half life , Parent nuclei will become half of
Which is equal to .
So, Parent nuclei have to go through Two half-lives.
The number of grams in 1.70 moles of Ca(NO₃)₂ is 384.2 grams
<h3>How to determine the mass of Ca(NO₃)₂</h3>
The mole of a substance is related to it's mass and molar mass according to the following equation:
Mole = mass / molar mass
With the above formula, we can determine the mass of Ca(NO₃)₂ as illustrated below:
- Mole of Ca(NO₃)₂ = 1.70 moles
- Molar mass of Ca(NO₃)₂ = 40 + 3[14 + (16 × 3)] = 40 + 3[14 + 48] = 40 + 3(62) = 40 + 186 = 226 g/mol
- Mass of Ca(NO₃)₂ = ?
Mole = mass / molar mass
1.70 = Mass of Ca(NO₃)₂ / 226
Cross multiply
Mass of Ca(NO₃)₂ = 1.70 × 226
Mass of Ca(NO₃)₂ = 384.2 grams
Thus, the mass of 1.70 moles of Ca(NO₃)₂ is 384.2 grams
Learn more about mole:
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<em>Transparent because you can see right through it </em>
Answer:
1 mole of iron =6.023×10^23 particles
1 particles of iron=1/6.023×10^23 mole
7.46×10^25 particles =1/6.023×10^23×7.46×10^25
=1.238×10^48 mole is a required answer.
Answer:
B. Similar fossils were found in different continents.
