Atomic structure Flashcards
What do atoms consist of?
Proton (nucleus)
Neutron (nucleus)
Electron (orbital shell)
Are atoms eelctrically neutral?
Yes - the number of protons (+) = number of electrons (-)
Relative masses
proton - 1
neutron - 1
electron 1/1860
What does the mass number mean?
Number of protons + neutrons
atomic number
number of protons
an atom is
Smallest particle of an element that retains the chemical property of that element atoms cant be broken down into cheically simpler pieces)
an ion is
an electrostatically charged species formed by an atom losing or gaining electron(s)
An isotope is
Atoms with the same atomic number but different mass number
different number of neutrons
different physical properties (same chemical)
(neutrons don’t affect chemistry of an atom)
What are the two different types of istopes
Radioactive isotopes-
- Used for carbon dating
- used to meaure thickness of materials
- cancer treatment
- used as energy in nuclear power stations
Non-radioactive isotopes-
Key facts on electric configurations
- Atoms are arranged in order of increasing atomic number in the periodic table
- Atoms have same amount of protons and electrons
- number of electrons = atomic number
- Electrons are found in shells of 2,8,8,2 etc.
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what does the period number represent
number of electron shells
what does the group number represent?
number of electrons in the outer shell
Two elements or more chemically combined
create an ion
What is a noble gas
Are elements that have full outer shells and are thus unreactive because they dont need to lose or gain electrons
other elements often lose/gain electrons to gain noble gas status
The valence (outer shell) of electrons are responible for
The chemical properties of an element
