An element x has two isotopes. x–15 has 7 protons and 8 neutrons. determine the atomic number and mass number of the second isotope, which has 10 neutrons in its nucleus. a. atomic number = 8; mass number = 9 b. atomic number = 8; mass number = 17 c. atomic number = 7; mass number = 17 d. atomic number = 7; mass number = 15

c. Atomic number = 7; mass number = 17  

The atomic number of the first isotope is 7.

Isotopes of the same element have the same atomic number, so the atomic number of the second isotope must also be 7.

Mass number = no. of protons + no. of neutrons, or

A = p + n

∴ A = 7 + 10 = 17

Options “a.” and “b.” have the wrong atomic numbers, and option “d.” has the wrong mass number.

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 .