1. Daily science
Naturally occurring europium (Eu) consists of two isotopes with a mass of 151 and Europium-151 has an abundance of 48.03% and Europium-153 has an abundance of 51.97%. What is the atomic mass of europium?
Write the following elements using short hand notation:
Helium
Tin
**PSAT and MJM

2. Radioactivity
Pg. 37

3. Radioactivity
Reactions which involve a change in an atom’s nucleus are called nuclear reactions.
Radioactivity- the spontaneous emission of radiation (rays and particles)
By emitting radiation, atoms of one element can change into atoms of another element.
Happens because of unstable nuclei
The element undergoing decay is called the parent nuclei
New element is called the daughter nuclei

4. Radioactive Decay Spontaneous process (doesn’t require energy)
Nuclei change until there is a stable product.
Half-life- the time it takes for ½ of a radioactive isotope to decay into its stable products.
Ex. If gallium has a half-life of 68.3 minutes, how much of a 10.0 mg sample is left after 1 half life? After minutes? After 3 half-lives?

5. Types of Radiation Alpha radiation-  Beta radiation-β
Gamma radiation- γ

7. Alpha Radiation Particle deflected toward a negatively charged plate
Alpha particles ( )
Equivalent to a helium-4 nucleus
Decay equation:
Represented by a nuclear equation

8. Beta Decay Deflected toward a positive plate Fast moving electrons ( )
Beta decay results in the creation of a new atom

9. Gamma Radiation
High-energy radiation that possess no mass and are denoted by the symbol 0
Not deflected when passed through a plate
Usually accompany alpha decay

11. If nitrogen has a half life of 145 years, how much of a 78 g sample will be left after 580 years?
Write a nuclear equation for alpha decay for Pb-207.
Write a nuclear equation for beta decay for the element Carbon-14.