All of the following statements are true of nuclear fusion except... Select one:
a. Extremely high temperatures are needed to start the reaction.
b. Hydrogen, the reactant, is scarce.
c. Two light nuclei react to form a heavier nucleus.
d. The products of the process may be radioactive.

d) the products of the process may be radioactive

Explanation:

nuclear fusion begins with two light nuclei that are combined to form larger nuclei. fusion required extremely high temperatures to give hydrogen atoms enough energy to overcome repulsion between the protons. In fusion, the reactant of Hydrogen is scare because Hydrogen atoms combine to form Helium atoms, neutrons, and extreme amounts of energy.

As said, fusion created large amounts of energy and the fuel is found on Earth, fusion produces no radioactive waste since atoms are combining.

for instance, fusion occurs naturally in stars, such as the sun. the earth gets its heat source from nuclear fusion, therefore if fusion created radioactive waste, there would not be life on earth.

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

catya that's not even a b or c