Question 9 of 10 Which of the following statements are true of nuclear energy and reactors?
Check all that apply.
O A. Nuclear reactors on Earth use fusion reactions to produce energy.
B. Nuclear fission reactions use only a small amount of material to
produce a large amount of energy.
C. Nuclear reactors use controlled reactions.
D. Nuclear fission is done by joining nuclei together into a bigger
nucleus.

B. Nuclear fission reactions use only a small amount of material to

produce a large amount of energy.

C. Nuclear reactors use controlled reactions.

Explanation:

Nuclear reactors are devices that contain and control nuclear chain reactions while releasing heat produced from these nuclear chain reactions at a controlled rate.

A nuclear power plant uses the enormous amount of heat that are produced from the nuclear chain reactions occurring in the nuclear reactor to turn water into steam, which then drives turbine generators that generate electricity.

The nuclear chain reactions occurring in the nuclear reactor are fission chain reactions. A nuclear fission reaction is a reaction in which a larger atom is split into two or more smaller atoms when bombarded with energetic neutrons resulting in the release of large amounts of energy and more neutrons. The neutrons released split more atoms of the larger atom into smaller atoms in what is known as a chain reaction. This reaction is controlled by means of moderators. A moderator helps slow down the neutrons produced by fission to sustain the chain reaction.

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.

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.