A substance appears to be pure. Which of the following cannot be true. The substance is a mixture.
The substance is an element.
The substance is a compound.
The substance has mass.

If blood contains 150g of hemoglobin per liter of blood, how much hemoglobin would be contained in 10 ml of blood

The chemical bond connecting one nucleotide with the next one along the nucleic acid chain is called a

Clyde and marilyn are riding a roller coaster. during which section(s) of the track is their potential energy converted to kinetic energy? a. from point b to point c only b. from point b to point d only c. from point a to point b only d. from point a to point b and from point c to point d