This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: Compared to the Sun, older stars contain what proportion of elements heavier than hydrogen and ... (Read 79 times)

Davideckstein7

  • Hero Member
  • *****
  • Posts: 555
on: Jul 27, 2018
Compared to the Sun, older stars contain what proportion of elements heavier than hydrogen and helium?
 
  A) a higher proportion
  B) exactly the same proportion
  C) they contain absolutely no heavy elements at all
  D) a lower proportion

Question 2

At present the universe is expanding, but we are not certain if this expansion will continue forever, come to a stop, or if the universe will ultimately collapse back into itself.
 
  What observational tests are possible to test among these three possibilities?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

Mholman93

  • Sr. Member
  • ****
  • Posts: 328
Reply #1 on: Jul 27, 2018
Answer to Question 1

D

Answer to Question 2

The possibilities can be tested by measuring the density of the universe. If the density is too low the universe expands forever; if too high the universe stops and collapses. Also, measuring the amount by which the rate of past expansion differed from the current rate (by studying redshifts) can reveal the rate at which expansion is slowing and so what will happen.


Davideckstein7

  • Member
  • Posts: 555
Reply 2 on: Jul 27, 2018
Excellent

steff9894

  • Member
  • Posts: 337
Reply 3 on: Yesterday
Thanks for the timely response, appreciate it

« previous next »
 

Did you know?

Computer programs are available that crosscheck a new drug's possible trade name with all other trade names currently available. These programs detect dangerous similarities between names and alert the manufacturer of the drug.

Did you know?

As many as 28% of hospitalized patients requiring mechanical ventilators to help them breathe (for more than 48 hours) will develop ventilator-associated pneumonia. Current therapy involves intravenous antibiotics, but new antibiotics that can be inhaled (and more directly treat the infection) are being developed.

Did you know?

Most fungi that pathogenically affect humans live in soil. If a person is not healthy, has an open wound, or is immunocompromised, a fungal infection can be very aggressive.

Did you know?

There used to be a metric calendar, as well as metric clocks. The metric calendar, or "French Republican Calendar" divided the year into 12 months, but each month was divided into three 10-day weeks. Each day had 10 decimal hours. Each hour had 100 decimal minutes. Due to lack of popularity, the metric clocks and calendars were ended in 1795, three years after they had been first marketed.

Did you know?

The U.S. Pharmacopeia Medication Errors Reporting Program states that approximately 50% of all medication errors involve insulin.

These older adults are participating in an exercise class at their assisted-living facility These older adults are participating in an exercise class at their assisted-living facility
Evolution of Stars Off the Main Sequence Evolution of Stars Off the Main Sequence
Living arrangements of older adults in the United States vary widely depending on gender and ... Living arrangements of older adults in the United States vary widely depending on gender and ...
Hydrogen Bond Hydrogen Bond
After elections were held, it was desired to estimate the proportion of voters who regretted ... After elections were held, it was desired to estimate the proportion of voters who regretted ...
Skeletal Elements of Early Reptile Skeletal Elements of Early Reptile
Video: Resting membrane potential - electrical polarity and maintenance requirements

For a complete list of videos, visit our video library