Pure substances cannot be separated by physical means into simpler substances. True or False?

When determining the shape of a molecule, it is important to draw a lewis dot structure first in order to see the total number a. electrons within the moleculeb. bonding and unshared pairs around central atomc. unshared pair within the molecule( i really need it )

Which step in naming unsaturated hydrocarbons is used for alkenes but not alkynes

Describe the difference between a. a hypothesis and a theory and b. an observation and an experiment.