Atomic Structure Flashcards
what are atoms?
smallest component of an element having the same chemical properties of that element
why are atoms electrically neutral?
no. of p = no. of e
how do sub-atomic particles behave in an electric field?
protons:
deflected towards negative plate
neutrons:
no charge, thus they remain unaffected
electrons:
deflected towards positive plate, much lighter than protons; deflected to a larger extent
what is nucleon/mass number?
total number of protons and neutrons in nucleus of an atom
what is atomic/proton number?
number of protons found in nucleus of atom
what is electronic structure?
arrangement of electrons in the different electron shells of an atom
what is valence/outermost shell?
shell farthest from nucleus
what are valence electrons?
electrons in valence shell
what are properties of electron shells?
nearer the shell to the nucleus, lower the energy level (shells filled in order of increasing energy level)
each shell numbered 1, 2, 3… outwards from nucleus
*valence electrons determine chemical properties
what are groups and periods?
groups (1, 2, 13-18) (vertical): same no. of valence electrons
periods (horizontal): same no. of electron shells
what are isotopes?
atoms of the same element with the same number of protons but different number of neutrons
what changes are there to the properties of isotopes?
identical chemical properties as the number of valence electrons is the same
different physical properties as they have different masses due to a different number of neutrons
what are ions?
atom or group of atoms that have an electrical charge
what is the charge of sodium?
Na⁺
what is the charge of calcium?
Ca²⁺
what is the charge of oxygen?
O²⁻
what is the charge of nitrogen?
N³⁻
what is the charge of sulfate?
SO₄²⁻
what is the charge of carbonate?
CO₃²⁻
what is the charge of nitrate?
NO₃⁻
what is the charge of hydrogen?
H⁺
why are noble gases extremely unreactive?
noble gas configuration, making them very stable
how are cations formed?
atoms of metals tend to form cations by losing their valence electron(s) to attain the noble gas configuration
*groups 1, 2, 13
*easier to gain 1-3 than to lose 5-7
*positive charge arises as there are more protons than electrons
how are anions formed?
atoms of non-metals tend to form antions by gaining valence electron(s) to attain the noble gas configuration
*groups 15-17
*easier to lose 1-3 than to gain 5-7
*negative charge arises as there are more electrons than protons
