Answer:
Rock Y
Explanation:
The rock that is older shall be determined based on the number of half lives it has witnessed. A half life is simply the amount of time required for a sample to decay to half of its original mass.
Rock X
From 100% uranium, it decays to 50% uranium. This means it went through just one half life.
Rock Y
From 100% uranium to 25% uranium
100 --> 50 (first half life)
50 --> 25 (second half life)
This means it wen through 2 half lives.
Rock Y is older than Rock X
There are following layers in earth atmosphere
a) Troposhere: the innermost layer or lowest part of atmosphere
b)stratosphere: next to troposhere
c)mesosphere:above stratosphere, here lowest temperature is observed
d)Thermosphere and Ionosphere: This layer allows long distance radio communication
e)Exosphere: this layer separates outer space from earth's surface.
There’s only one measurement the question doesn’t make sense
Answer:
I dont know the first blank but I know the second one is groups and the last one is periods.
