Its a 50% chance that approx 1/2 of the pennies will land on tails. The next toss will result the same. and so on and so on. showing how a reaction would slowly eliminate 1/2 of the remaining lives per reaction, until nothing is left. I think it is a good stimulation.
The mass number is the summation of number of proton and neutron present in a nucleus of an atom. For the neutral atom the number of positive charge (number of proton) must be equal to the number of electrons. The number of electrons present in an atom is the atomic number of the atom. The standard way to express the mass number (a) and atomic number (m) of a atom (say X) is 
. Now for silicon number of electron or atomic number is 14. And the mass number (a) given 29. Thus the expression nucleus of silicon will be 
They can decay through one of three ways:
alpha decay
beta decay and
gamma decay
ALPHA- particle with two neutrons and two protons is ejected from the nucleus of the radioactive atom. this particle released is called an alpha particle. Only occurs with heavy metals.
BETA- pretty much when a proton is transformed into a neutron, or vise versa. in a beta minus decay, the nuetron decays into a proton and in a beta plus decay, a proton decays into a neutron
GAMMA- the nucleus changes from a high energy state to a low energy state by releasing electromagnetic radiation (photons). the number of protons and neutrons stay the same during this reaction therefore the element is still the same.
1. A radical is a reactive intermediate with a single ____________ electron, formed by ____________ of a covalent bond.
1. A: Unpaired, and homolysis
2. Allylic radicals are stabilized by ____________ , making them ____________ stable than tertiary radicals.
2. A: Resonance, and more
3. A compound that contains an especially weak bond that serves as a source of radicals is called a radical ____________ .
3. A: Initiator
4. Treatment of cyclohexene with N-bromosuccinimide in the presence of light leads to ____________ by ____________ intermediates.
4. A: Allylic substitution by radical
