The Atom/NuclearStudy Guide Review

Complete the following table:

Subatomic Particle

Location Charge Relative Mass

Proton nucleus + 1 amuElectron outside

nucleusor

electron cloud

orshells

- 0 amu

Neutron nucleus o 1 amu

• The number of protons in an atom is its atomic number

• The number of protons + neutrons in an atom is its

Mass number or atomic mass

• What are isotopes? Atoms of the same element with different masses; neutrons are different

• How does mass number differ from atomic mass?

Relatively the same

Use the periodic table to identify the following elements:• (a) 47 protons -- Ag• (b) 95 electrons -- Am• (c) atomic number = 28 -- Ni• (d) 6 protons and 8 neutrons -- C

Remember – A=P=E

Atomic number = Protons = Electrons

Complete the following table:

Isotope Name

SymbolicNotation

Number of Protons

Number of Electrons

Number of Neutrons

Oxygen-16 16 O8

8 8 8

Nitrogen-16 16 N7

7 7 7

Bromine-80 80 Br35

35 35 45

Define the following terms:• Radioactivity – atoms with unstable nuclei

that emit Alpha (α), Beta (β) or Gamma (γ) particles

• Radioisotopes – isotopes of an element that undergo radioactive decay

• Half-life – the time it takes for ½ the particles to decay

• Nuclear fission – splitting apart of a nucleus

• Nuclear fusion – coming together of nuclei (example – surface of the sun)

• Nuclear reactions involve changes in an atom’s nucleus, where chemical reactions do not.

Complete the following table:Type of

RadiationSymbol What is it? Can be

stopped byPenetratin

g power

Alpha α 4 He2

Helium atom

Paper LOW

Beta β 0 e-1

Electron Aluminum MEDIUM

Gamma γ γ Energy 1” lead HIGH

Write a balanced nuclear equation for each of the following decays• Alpha decay of polonium-218

218 Po → 4 He + 214 Pb84 2 82

• Beta decay of potassium-4343 K → 0 e + 43 Ca19 -1 20

• The half-life of polonium-210 is 138.4 days. How many milligrams of polonium-210 remain after 415.2 days if you start with 2.0 mg of the isotope?

• Days = 415.2 days• ½ life = 138.4 days• Start with = 2mg

2 1 .5 .25

138.4 + 138.4+138.4 = 415.2

• The half-life of cobalt-60 is 10.47 min. How many milligrams of cobalt-16 remain after 104.7 min if you start with 10.0 mg?

.0097

• Radon-222 undergoes the following decay series:

–ααββαββα– What element is formed?