Half-life and Radioactive DecayBy. Aarfa and Brooke

History

The “radioactive half-life” was found in 1907, by a scientist named Ernest Rutherford.

He was born on August 30th, 1871 in Nelson, New Zealand.Rutherford was both a chemist and physicist and is known as the "father of nuclear physics”.

Out of his many achievements he was knighted in the New Year's Honours List for 1914 and he was awarded the Noble Prize in 1908 for his investigations into the disintegration of the elements, and the chemistry of radioactive substances

He on died October 19th, 1937 at the age of 66 of a strangulated umbilical hernia and couldn’t be treated because he was a lord.

Half-Life Decay

The “Half-Life” of anything is the amount of time that a substance’s total isotopes is halved.

What are Isotopes?

Atoms are particles of matter. Protons are positively charged particles and electrons are negatively charged particles. When there are equal amounts of negative and negative particles it makes an atom with a neutral charge which is what a neutron is. When an atom is missing or has an extra neutron it makes an isotope. Isotopes are still the same element, they’re just a little different from the other atoms in the same element.

Example

Carbon-14 is a radioactive isotope of carbon with a nucleus containing 6 protons and 8 neutrons. It has a half-life of about 5700 years which means that a 100g sample will decay as shown below/here: 0 years -> 100g 5700 years -> 50g 11 400 years -> 25g 17 100 years -> 12.5g

Real Life Uses

Half-life is useful to determine geological time, which helps in the carbon dating in such things like rocks. Half-life is also used in Radioactive decay….

Radioactive Decay

Radioactive Decay is classified as the, "spontaneous transformation of one element into another” There are a number of ways that this can happen and when it does, the atom is forever changed. There is no going back -- the process is irreversible.

This means that the disintegration of the radioactive material is totally random and nothing can predict it, except statistic probability and once the change is complete, you can’t change it back.

An example of the process of ‘radioactive decay’ is very similar to popcorn, once changed there’s no way you can put it back into a kernel again.

Experiment

We will now be conducting an experiment to prove the point of the randomness and spontaneous-ness involved in radioactive decay.

Everyone will be given a penny, and when told, you’ll all flip them until we’re out of people. Only people with a coin facing “head” up can stay standing. Those who get tails will sit down.

Question Time!!!

1. What is the name of the person who "discovered" the half-life?

a) Albert Einstein

b) Isaac Newton

c) Ernest Rutherford

d) Gabe Newell

Answer:

c) Ernest Rutherford

2. When was he born and when did he die?

a) August 30th , 1871, October 19th , 1937

b) August 29th , 1845, November 17th, 1912

c) December 24th, 1819, September 13th, 1901

d) February 14th, 1850, January 12th, 1950

Answer:

a) August 30th , 1871, October 19th , 1937

3. What is it about radioactive decay that makes it hard to predict?

a) Because it hates you

b) Because it’s spontaneous

c) Because it has too many protons

d) Because it’s stupid

Answer:

b) Because it’s spontaneous

4. What is a example that was listed of something like the radioactive process?

a)Cake

b)Pepsi

c)Canada

d)Popcorn

Answer:

d) Popcorn

Thanks for watching!!!!

Bibliography

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"Neutron Madness." Chem4Kids.com: Atoms: Isotopes. N.p., n.d. Web. 23 Nov. 2013. <http://www.chem4kids.com/files/atom_isotopes.html>.

"Radioactive Decay." Radioactive Decay. N.p., n.d. Web. 23 Nov. 2013. <http://serc.carleton.edu/quantskills/methods/quantlit/RadDecay.html>.

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