Answer:
It will take 6.6 hours for 75% of the lead to decay.
Explanation:
The radioactive decay follows first order rate law
The half life and rate constant are related as
The rate law for first order reaction is
Where
A0 = initial concentration = 1 g
At= final concentration = 0.25 g (as 75% undergoes decay so 25% left]
Answer:
The answer is (C) There are more solute molecules than water molecules.
Explanation:
A saturated solution is one in which no more solute can be dissolved or disintegrated into the solvent. When or if the ozone stops being dissolved in the water, it implies that the water has already taken on more ozone molecules than it can contain, meaning there are more solute molecules (ozone molecules) than there are solvent molecules (water molecules).
Answer:
asking about subjective matters
possibly leading to a testable hypothesis
addressing a gap in knowledge
I got soo confused about that last part. I didn't know if that was an option or something you needed to be answered.
Descriptive investigations are not repeatable because they are based only on observations made at a single point in time. The results may vary at a different time. In addition, descriptive investigations do not contain variables that may indicate cause-and-effect relationships.
A neutral nitrogen atom has 7 protons.