Chemistry, 04.05.2021 16:30 oliviaprejean18
In the parts that follow, use the following abbreviations for time:
Measure of time Units of time
minutes min
hours h
days d
years yr
Required:
a. You are using a Geiger counter to measure the activity of a radioactive substance over the course of several minutes. If the reading of 400. counts has diminished to 100. counts after 25.8 minutes , what is the half-life of this substance?
b. An unknown radioactive substance has a half-life of 3.20 hours . If 17.1 g of the substance is currently present, what mass A0 was present 8.00 hours ago?
Answers: 2
Another question on Chemistry
Chemistry, 22.06.2019 00:30
In numbering carbon atoms in the parent chain of a hydrocarbon, why would you number from right to left, rather than left to right
Answers: 1
Chemistry, 22.06.2019 21:20
Phosgene (carbonyl chloride), cocl2, is an extremely toxic gas that is used in manufacturing certain dyes and plastics. phosgene can be produced by reacting carbon monoxide and chlorine gas at high temperatures: co(g) cl2(g)⇌cocl2(g) carbon monoxide and chlorine gas are allowed to react in a sealed vessel at 477 ∘c . at equilibrium, the concentrations were measured and the following results obtained: gas partial pressure (atm) co 0.830 cl2 1.30 cocl2 0.220 what is the equilibrium constant, kp, of this reaction
Answers: 2
Chemistry, 22.06.2019 22:30
Vi limitens. vastery test select the correct answer. which statement explains why large atoms are more reactive than small atoms? a. large atoms have valence electrons farther from the nucleus and lose them more readily. b. large atoms have greater ionization energy, which they can utilize during a reaction. c. large atoms have a greater number of electrons that they can lose during a reaction. d. large atoms have more energy levels, so they have more energy to pass on in a reaction. reset next
Answers: 3
Chemistry, 22.06.2019 22:30
Consider a culture medium on which only gram-positive organisms such as staphylococcus aureus colonies can grow due to an elevated nacl level. a yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the ph as a result and changing the color of a ph indicator chemical. this type of medium would be referred to as a differential and enrichment culture.
Answers: 2
You know the right answer?
In the parts that follow, use the following abbreviations for time:
Measure of time Units of time<...
Questions
History, 04.09.2020 20:01
Biology, 04.09.2020 20:01
Computers and Technology, 04.09.2020 20:01
Chemistry, 04.09.2020 20:01
English, 04.09.2020 20:01
English, 04.09.2020 20:01
