Which of these is a qualitative observation? a. The boy is 5 feet tall.
b. There are six birds in the tree.
c. The birds are tiny.
d. There are more blue birds than black birds.

Different isotopes indicate that an element will have different numbers of

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?

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.