The period of the wave above is

What is the name for a substance formed in a chemical reaction

During which phase does earth see more than half of the moon's surface? 1)first quarter2)third quarter3)waxing gibbous4)waning crescent

Consider the classification levels of a human. eukarya ,animalia ,chordata ,mammalia ,primates, hominidae ,homo ,sapiens .which is the most specific taxonomic level in the classification system above? a sapiens b homo c hominidae d primates