the periodic table Flashcards
what does the group that the elements are in tell us about the element?
the number of valence electrons in an atom of that element
what does the period that the elements are in tell us about the element?
the number of electron shells/valence shells in an atom of that element
does the number of protons increase or decrease across the periodic table?
increase
does the number of valence electrons increase or decrease across the table?
increase
does the metallic property increase or decrease across the periodic table? why?
decrease
- on the left side of the periodic table, metal atoms tend to lose electrons and form positive charged ions
- moving across the period, there is higher tendency for elements to gain electrons as elements are non-metals and form negative charged ions
does the number of protons increase or decrease DOWN the periodic table?
increase
does the atomic size/radius increase or decrease DOWN the periodic table?
increase
-number of electron shells increases
does the number of valence electrons increase or decrease DOWN the periodic table?
remains the same!
are chemical reactions similar or different DOWN the group?
similar as they have the same number of valence electrons
what are sub-atomic particles?
protons, neutrons, electrons
define isotopes
atoms of the same element having the same number of protons but different number of neutrons
why are fluorine, chlorine and iodine placed in the same group?
these elements have 7 valence electrons
are elements in group 1 soft or hard
soft, can be cut with a knife
-shiny and silvery but quickly tarnish when cut
do elements in group 1 have low or high density?
low density
how can we prevent group 1 metals to react with water and oxygen gas?
store in oil
does the melting and boiling points increase or decrease down group 1?
decrease
does reactivity increase or decrease down group 1?
increase
colour and physical state of fluorine at room temperature
yellow, gas
colour and physical state of chlorine at room temperature
greenish yellow, gas
colour and physical state of bromine at room temperature
reddish brown, liquid
colour and physical state of iodine at room temperature
purplish black, solid
colour and physical state of astatine at room temperature
black, solid
does the density increase or decrease down group VII?
increase
does melting and boiling point increase or decrease down group VII?
increase
does reactivity increase or decrease down group VII?
decrease
use of helium
fill up balloons
use of neon
entertainment lights
use of argon
provide inert atmosphere welding/ light bulbs
why are noble gases unreactive?
atoms of noble gases do not need to lose, gain or share electrons
stable electronic configuration
what is formed when aqueous chlorine is added to sodium bromide? why?
a reddish brown solution is formed due to the formation of bromine. chlorine is more reactive than bromine. hence it displaces bromine from sodium bromide
Aqueous chlorine + sodium bromide → sodium chloride +bromine
what is formed when aqueous chlorine is added to potassium iodide? why?
a brown solution is formed due to the
formation of iodine. chlorine is more reactive than iodine. hence it displaces iodine from potassium iodide.
Aqueous chlorine + potassium iodide → potassium chloride + iodine
what is formed when aqueous chlorine is added to sodium fluoride? why?
no reaction. fluorine is more reactive than chlorine. hence chlorine is unable to displace fluorine from sodium fluoride
Cl2(aq) + 2NaF(aq) → no reaction
