Which of the following reveals a pattern observed by scientists?
a. hot springs are warmed year-round by melted rock.
b. a woman can get pregnant at a certain time each month.
c. mud sometimes smells like rotten eggs because of chemicals
inside the mud
d. waves on the ocean can be very tall.

Both 1,2−dihydronaphthalene and 1,4−dihydronaphthalene may be selectively hydrogenated to 1,2,3,4−tetrahydronaphthalene. one of these isomers has a heat of hydrogenation of 101 kj/mol (24.1 kcal/mol), and the heat of hydrogenation of the other is 113 kj/mol (27.1 kcal/mol). match the heat of hydrogenation with the appropriate dihydronaphthalene.

Asample of aluminum foil contains 8.60 × 1023 atoms. what is the mass of the foil?

This drawing shows a human body system. what is the primary function of this body system?