# 1ปรนัยWhat is the smallest unit of an element that retains its chemical properties?MoleculeAtomCompoundMixture
# 2ปรนัยWhich of the following is a characteristic of metals?BrittlePoor conductor of electricityDuctileNon-malleable
# 3ปรนัยWhat is the main idea behind Mendeleev's periodic table?Elements are organized by atomic numberElements are organized by atomic massElements are grouped by colorElements are arranged randomly
# 4ปรนัยWhich group of elements is known for being unreactive?HalogensAlkali MetalsNoble GasesTransition Metals