Why does the amplitude of a seismic wave usually decrease as the wave moves away from the epicenter

What semimetal can form four single covalent bonds.

1. calculate the approximate enthalpy of the reaction in joules. estimate that 1.0 ml of vinegar has the same thermal mass as 1.0 ml of water. iqnore the thermal mass of th sodium bicarbonate. note: it takes about 4.2 joules () to change 1.0 gram (1.0ml) of water 1.0 c

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