Answer:
Three half lives.
Explanation:
Given data:
Number of half lives passed = ?
Amount of parent isotope left = 12.5%
Solution:
At time zero = 100%
At 1st half life = 100%/2 = 50%
At second half life = 50%/2 = 25%
At third half life = 25%/2 = 12.5%
It means three half lives would passed.
Answer:RDA: The Recommended Dietary Allowance (RDA) for adults 19-51+ years is 400-420 mg daily for men and 310-320 mg for women. Pregnancy requires about 350-360 mg daily and lactation, 310-320 mg.
Explanation:
The magnitude of the heats of vaporization, fusion and sublimation of a substance reflect the intermolecular forces.
What are intermolecular forces?
- “Intermolecular forces” is used to describe the forces of attraction between atoms, molecules, and ions when they are placed close to each other.
- Atoms, molecules, and ions are strongly attracted to one another and move toward one another when intermolecular interactions are strong. These are more frequently encountered in states that are condensed, like liquid or solid.
- Atoms, molecules, or ions do not have a significant attraction to one another and move far apart when intermolecular forces are weak.
Learn more about the intra- and intermolecular forces with the help of the following link:
brainly.com/question/26701678
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Answer: 12 atoms
Explanation: the equation has 6H2 i.e
6*2 = 12
