1. Calculate the wavelength of an x-ray which has a frequency of 10^16 Hz(adsbygoogle = window.adsbygoogle || []).push({});

2. Calculate the Energy associated with an x-ray with a frequency from Question 1.

* I dont know how to do this, but from looking at the electromagnetic spectrum, it tells you. But i want to know how to calculate it.

-------------------------------

A radioactive source (with a half life of 5 days) has an initial activity of 4000 counts/min.

3. Determine the activity after 10 days

4. If the initial quantitiy of radioactive material is 200gms, determine the amount left after 15 days have elapsed.

5. Convert 4000 counts per min into Bq's

* I know on half-life, the amount of is halved, but the activity is 4000 counts/min. so i divided 4000/60 = hrs, then divide by 24 to give days, then divide by 10 to give 10 days. but the half life is 5 days so not really sure what to do, someone can please show me how to do question 3,4,5

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Radiation and nuclear energy

**Physics Forums | Science Articles, Homework Help, Discussion**