Why is the gravitational slingshot important to space exploration? A. to allow spacecraft to refuel without stopping
B. to help spacecraft increase velocity without using additional fuel
C. to make spacecraft weightless
D. to make spacecraft safer

B. To help spacecraft increase velocity without using additional fuel

Explanation:

The gravitational slingshot is the use of the gravity of a planet or other astronomical object to alter the path and velocity of a spacecraft. It  also helps slow down a spacecraft, change their orbits into directions they could never reach, or accelerate to high velocities (without using additonal fuel).

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

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.