The isotope, tritium, has a half-life of 12.3 years. Assume we have 10 kg of the substance. How much tritium will be left after 30 years

Explanation:

Half life = 12.3years

Time =  30 years

Basically half life is the amount of time taken for the intial concentration to be reduced to half.

First half life = 12.3 years = 10/2 = 5 Kg left

Second half life = 24.6  years= 5/2 = 2.5 Kg left

Third half life = 36.9 years = 2.5 / 2 = 1.25 Kg left

This means that after 30 years, the amount of tritium left would e betweem 1.25kg to 2.5 kg.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

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