P4

Subdecks (2)

Cards (58)

What is the basic structure of an atom
A positively charged nucleus composed of protons and neutrons surrounded by negatively charged electrons
Where is the most of the mass of an atom concentrated
Nucleus
How can the electron arrangements of the nucleus change
The absorption of electromagnetic radiation causes electrons to move further from the nucleus
The emission of electromagnetic radiation causes electrons to move closer
Why do atoms have no overall charge
The number of protons is equal to the number of electrons
What is atomic number?
The number of protons in an atom's nucleus.
What is a mass number?
The total number of protons and neutrons in an atomic nucleus.
How do atoms form positive ions
Losing electron(s)
What is radioactive decay 
The random process by which nucleus gives out radiation to become stable
What is activity 
The rate at which a source of unstable nuclei decay
What is the unit for activity
Baquerel, Bq
What is count rate 
The number of decays recorded each second by a detector
What is an alpha particle
A helium nucleus which is two neutrons and two protons
What is a beta particle
A high-speed electron ejected from the nucleus as a neutron turns into a proton
What is a gamma ray
Electromagnetic radiation from the nucleus
What is half life
The time it takes for number of nuclei of the isotope in a sample to half
What is contamination 
The unwanted presence of materials containing radioactive atoms on other materials
What is irridation  
The process of exposing an object to nuclear radiation
The irridated object does not become radioactive

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