Suppose that you are a scientist who studies climate changes. While examining the rings of tree trunks, you notice several very large tree rings. What can you conclude about the climate during those years?

Which of the following statements is not true? • a. covalent compounds have low melting and boiling points. • ob. covalent bonds between atoms of a compound are relatively weak compared to bonds between molecules. • c. covalent bonds occur between nonmetals. • d. covalent compounds are often gases or liquids.

Which of the following is true for the actual yield of a reaction? it is always calculated as a ratio. it is the yield from the excess reactant. it is the yield from the limiting reactant. it is always less than the theoretical yield.

Identify arrows pointing to bonding electrons. done h-0-0-h ) intro