Half-life of a radioactive substance is the time required to reduce the amount of substance to half of its initial amount.
In present case, half-life is material is given as 1000 years and initial amount of material is given as 400 kg
Answer 1) Since, half-life of radio-active substance is 1000 years, therefore after 1st half life, amount of the material will be left to half the initial amount. Hence, amount of substance left after 1000 years = 400/2 = 200 kg.
Answer 2) For 2000 years, radioactive material has crossed 2 times the half life. Therefore , amount of the material will be left to 1/4 the initial amount. Hence, amount of substance left after 2000 years = 400/4 = 100 kg.
Answer 3) For 4000 years, radioactive material has crossed 4 times the half life. Therefore , amount of the material will be left to 1/16 the initial amount. Hence, amount of substance left after 4000 years = 400/16 = 25 kg.
Answer:
The black snakes will survive and reproduce while the orange snakes die out.
Explanation:
The orange snakes will be easier to see by their prey and predators, and therefore will die out while the black snakes thrive because of their camouflage.
A mixture is composed of more than one substance combined
A pure substance cannot be decomposed in any reaction
<span>Both are considered types of substances
</span>hope it helps you playa!
Answer:
The other electron must have anticlockwise spin.
Explanation:
According to the pauli exclusion principle, the two elecrton present in same orbital must have opposite spin.
If the one electron is clockwise the other must be in anti clockwise direction. The clockwise direction is represented by the sign +1/2 while anti clockwise direction is represented by -1/2.
According the pauli principle, the two electrons must have different fourth electronic quantum number. The electron in same orbital have same first three quantum number i.e, n=1 l=0 and ml =0 in case of first subshell.
