Identify two structural features of purines and pyrimidines. purines contain four ring nitrogen atoms. contain only two ring nitrogen atoms. contain two heterocyclic rings. contain only three ring nitrogen atoms. contain one heterocyclic ring. pyrimidines contain only two ring nitrogen atoms. contain two heterocyclic rings. contain four ring nitrogen atoms. contain one heterocyclic ring. contain only three ring nitrogen atoms. classify each molecule as a purine or a pyrimidine. purines pyrimidines answer bank

both adhesion and cohesion are attractions.

they are different in that adhesion is the force of attraction between the molecules of two different substances, whereas cohesion is the force of attraction between molecules of the same substance.

possible examples include capillary action, in which the adhesion between water and glass causes the water to rise in a narrow tube against the force of gravity.

because of hydrogen bonding, water is extremely cohesive.

this causes molecules on the surface of water to be drawn inward, which is why drops of water form beads on smooth surfaces.

hope this .

1.solid

2.carbon dioxide

3.helium

because u need two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei to form isotopes.

so since they all have the same shape? i mean maybe because m& m and reeses are both chocolates