- emission spectrum is the amount of electromagnetic radiation of each frequency it emits when it is heated (or more generally when it is excited). When the electrons in the element are excited, they jump to higher energy levels.
- Absorption spectrum is a technique used to find out what makes up a sample of a substance – in other words, a chemical analysis.
Answer: 2 (2 neutrons are produced).
Explanation:
1) In the left side of the transmutation equationa appears:
²³⁵U + ¹n →
I am omitting the atomic number (subscript to the leff) because the question does not show them as it is focused on number of neutrons.
2) The right side of the transmutation equation has:
→ ¹⁴⁴Ce + ⁹⁰Sr + ?
3) The total mass number of the left side is 235 + 1 = 236
4) The total mass number of Ce and Sr on the right side is 144 + 90 = 234
5) Then, you are lacking 236 - 234 = 2 unit masses on the right side which are the 2 neutrons that are produced along with the Ce and Sr.
The complete final equation is:
²³⁵U + ¹n → ¹⁴⁴Ce + ⁹⁰Sr + 2 ¹n
Where you have the two neutrons produced.