I NEED HELP ASAP Which of the following is an example of a task an astronomer might perform?

analyze satellite imagery
plan the orbit for a satellite
develop satellite quality standards
design a rocket to launch a satellite

Asolution contains 225 g of sodium chloride, nacl, dissolved in enough water to make a 0.25 l of solution. what is the molarity of the solution?

Sugar is dissolved in water. which is the solute? sugar neither both water

One of the hopes for solving the world's energy problem is to make use of the fusion reaction 21h +31h --> 42he + 10n + energy how much energy is released when 1 mol of deuterium is fused with 1 mol of tritium according to the above reaction? the masses of the atoms and the neutrons are as follows: 21h = 2.0140 amu 31h = 3.01605 amu 42he = 4.002603 amu 10n = 1.008665 amu. the speed of light is 2.9979 x 108 m/s.