Flimsy paper dealing with family storing atoms (9)
I believe the answer is:
onionskin
'flimsy paper' is the definition.
'onionskin' can be an answer for 'paper' (onionskin is a kind of paper). I am not sure about the 'flimsy' bit.
'dealing with family storing atoms' is the wordplay.
'dealing with' becomes 'on'.
'family' becomes 'kin' (synonyms).
'storing' means one lot of letters goes inside another.
'atoms' becomes 'ions' (ion is a kind of atom).
'on'+'kin'='onkin'
'onkin' going around 'ions' is 'ONIONSKIN'.
Can you help me to learn more?
(Another definition for onionskin that I've seen is " Very thin variety of paper".)