How many atoms of potassium are in 0.250 mol of potassium carbonate, k2co3?

In an investigation that uses the scientific method, which step immediately follows making a hypothesis? o summarizing the results o asking a question o making observations designing an experiment mark this and retum save and exit next submit

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.

Sum of brother and sisters age is 26. four times the brothers age is subtracted from three times the sisters age, the difference is 8. what are the ages of the brother and sister?