Which word or group of words is represented by the word "period”in the term periodic table?

Liquid water turns into water vapor at which step in the water cycle? a. precipitation o b. water run off c. evaporation d. condensation

Describe the two types of vascular tissue

The double bond between a carbon atom and two oxygen atoms (a molecule of carbon dioxide) has two characteristics. what are they? a.an ionic bond is formed between the oxygen and carbon atoms. b.four valence electrons are shared. c.two valence electrons are shared. d.valence electrons are shared between oxygen atoms.