Mrs. Johnston heated 5 grams of sugar. The sugar first looked shiny, and then it melted and became dark brown. Finally, all that was left
was a black, shiny residue. She then heated 5 grams of sand in the
same way. The sand's appearance did not change.
What explains these results?

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.

How will the emission of an alpha particle affect the atomic number of an atom

Which of the following statements about hybrid orbitals is or are true? choose all that apply. choose all that apply. under sp2 hybridization, the large lobes point to the vertices of an equilateral triangle. after an atom undergoes sp hybridization there is one unhybridized p orbital on the atom. the angle between the large lobes of sp3 hybrids is 109.5∘