My 9 year old daughter would like a simple explanation of what happens in a nuclear explosion?

Question

She is looking for a simple explanation with possibly diagrams (she is concerned because of the press regarding the North Korean test).

She is interested in how the explosion occurs, what is radiation, why does it last so long, and how does radiation kill people?

Answer 1

I agree with the Mother of a 9 yo...answer truthfully, but avoid gorey details.

You can "explain" a nuclear chain reaction by setting up ten dominoes like pins in a bowling alley. When you tip the first one over, it should knock down the two in the next row, these two then knock down the three in the third row; and they knock down the five in the last row. Each tipping domino represents an atom splitting.

That kind of thing happens in a nuclear chain reaction and causes the explosion because heat, light, and other stuff is created each time an atom (each domino) splits (topples over) and causes one or more other atoms to split. Like the one domino tipping ends up with five in the last row tipping, atoms cause more and more atoms to split in a nuclear chain reaction. Unlike the dominoes, there may be millions of atoms splitting in a nuclear chain reaction.

Further, when each atom splits, it crates energy that is released as heat, light, sound, radiation, and so on. A lot of radiation is just high energy light so to speak. Some of that high energy light (the radiation) zaps the things around it, like ground, stone, water, air, and such. That in turn causes these surroundings to radiate at lower energies than the radiation from the chain reaction. And lower energies last longer than higher energies, which is why radiated ground and such can stay radiated for long times.

As to killing people, use the high energy light analogy...radiation gives people a really really severe sun burn kind of burn. They can die if they get too much of that "sun burn" kind of thing from radiation. And because it is high energy, it will go through even sun screen, clothes, and dark glasses.

Answer 2

Everything we see, the table, the carpet, the trees, other people are made up of tiny things called atoms. For example, water is made up of lots and lots of molecules called H20. H20 is 1 hydrogen atom stuck together with 2 oxegen atoms.
H H H H
/ \ / \ / \ / \ This is Water
0 0 0 0 0 0 0 0
Every atom is made up of even tinyer things called sub atomic particles like electrons, protons and neutrons. For example the hydrogen atoms in water are made of 1 proton(P), stuck to 1 neutron(N) with 1 electron(E)spinning around them.
_______
| |
| PN E This is a hydrogen atom
|_______|

When you stick 2 pieces of paper together with glue, it is very hard to try too pull them apart. This is because there is a lot of energy holding the pieces of paper together. In an atom, there is also a lot of energy holding the sub atomic particles together. A nuclear bomb is full off uranium atoms. A detonator inside the bomb splits the uranium atoms apart. Now remember Ive just said that a lot off energy holds sub atomic particles together. So if we split these atoms apart all this energy is suddenly released. This energy is the explosion of a nuclear bomb. The thing with uranium atoms is they also release radiation. You know when you stand very close to someone, or to your cat or dog on a real cold night, you can sometimes feel the heat coming from thier body. This is radiation. Radiation from a nuclear bomb going off is much, much stronger though, and we cant really feel it as heat, but it is there. Why it lasts so long and how it kills people, Iam not entirely sure. Theres just one thing more I would like to say. Remember when you were younger, learning how to ride a bike. You were probably really concerned that would never do it properly. Always falling off, hurting yourself, very wobbly etc. But because you kept on trying you eventually got it. You may be concerned about the north korean test and this is fine, we all are. But what if we all did something about it, what if we all tryed to stop it. What could you do? How about writing a letter to the prime minister. How about getting all your friends and teachers to sign it aswell. Tell John Howard to put pressure on the north korean prime minister to stop. This could be a start, maybe you could think of something else aswell.

Answer 3

Maybe you should not be emotionally traumatizing your daughter with details about nuclear wars and radiation poisoning. Why would anyone watch the news? It's not as if you're going to do anything about it.

In all seriousness though, you should tell her that people in surrounding areas of the nuclear bomb explosions actually have a higher than average life span because of something dubbed "adaptive response". (I'm not kidding, google the words: [adaptive response radiation] for more information) Radiation isn't "bad", nuclear bombs are bad.

Answer 4

Atom bombs (which use nuclear fission) are weaker than hydrogen bombs (which use an atom bomb to trigger fusion). The North Koreans exploded an atom bomb with a yield 30 times smaller than the bomb we used on Hiroshima, and 100,000 times weaker than the biggest hydrogen bomb ever exploded. (See this: http://en.wikipedia.org/wiki/Tsar_Bomba )

Fission means that atoms break apart and the resultant pieces release a lot of energy. The pieces of atoms are various particles and some of them are atoms themselves. Some of these pieces move at high velocity and if they pass through your body, they can damage your cells in various ways.

Tell her that "hard" radiation from radioactive elements is more dangerous than the ultraviolet radiation that the Sun makes, or the radiation from your microwave oven. Tell her that your cells have DNA repair mechanisms that can fix most damage, and not to worry (unless you live in South Korea or Japan).

Answer 5

I would like to provide a brief explanation. However there are to many factors as related to her question. Size of the device (1kt to 50mt), Air vs.ground blast, type of radioactive core used, radiation types (alpha, beta, gamma, neutron), half differences, wind direction and speeds and other factors.

Perhaps short of her reviewing information on the net or a library book, you might sit down and review it with her.

Me, I would be honest and tell here that they are dangerous and devastating weapons but N. Korea does not (at least yet) have a delivery system (missile) capable of reaching the USA.

Answer 6

Jeesh! That's pretty heavy duty for a nine year old. I would try to steer her away from the details...don't lie to her, but rule of thumb is to answer truthfully only giving information for questions asked. Is it possible for you to just tell her that the testing was done underground - so there was no visible explosion. That the governments from all over the world are watching North Korea very closely and will do everything possible to prevent them from EVER seting one off that would hurt people.

Too much information can set small minds racing and worrying.

Answer 7

A nuclear bomb is like a mini ‘sun’ which burns only for a few seconds, and releases huge amount of energy in the form of heat, light and radiation.

Answer 8

Well i guess you can her that a nuke nevers touches ground.. They are pre set with a pressure switch, and for mass destruction they are detonated 850/1500 ft above the surface of the intended target.If there is a neculear war only 59% of earths pop will survive,then we will have to live in a preastoric time MERRY CHIRSTMAS ..........................................................