Answer:
Orbitals
Shells
Energy Levels
Explanation:
Elements in the same period will have the same energy levels which is the same as orbitals and shells.
- The period of an element indicates the energy level in an atom.
- Elements in period 1 will have one energy level or shell or orbitals.
- Down a group this is not the case.
- The energy level increases from top to bottom.
- As we go down the group, we are transiting from one period to another.
It is really easy if you look up an electron configuration table (one that looks like a periodic table) and then just go down the rows left to right, top to bottom, and just stop when you get to where the element is on the table.
C is a mixture!!!!!!!!!!!!!
Answer:
It increases when the concentration of reactants increases.
Explanation:
Increasing the concentration of reactants in a reaction increases the amount of reacting molecules or ions which would increase the rate of a chemical reaction. Reaction rate does depend on temperature. Increasing temperature also increases reaction rate because particles move faster with the increased kinetic energy to produce more collisions.
Answer:
0.9715 Fraction of Pu-239 will be remain after 1000 years.
Explanation:
Where:
= decay constant
=concentration left after time t
= Half life of the sample
Half life of Pu-239 = 
[
![\lambda =\frac{0.693}{24,000 y}=2.8875\times 10^{-5} y^{-1]](https://tex.z-dn.net/?f=%5Clambda%20%3D%5Cfrac%7B0.693%7D%7B24%2C000%20y%7D%3D2.8875%5Ctimes%2010%5E%7B-5%7D%20y%5E%7B-1%5D)
Let us say amount present of Pu-239 today = 
A = ?
![A=x\times e^{-2.8875\times 10^{-5} y^{-1]\times 1000 y}](https://tex.z-dn.net/?f=A%3Dx%5Ctimes%20e%5E%7B-2.8875%5Ctimes%2010%5E%7B-5%7D%20y%5E%7B-1%5D%5Ctimes%201000%20y%7D)
0.9715 Fraction of Pu-239 will be remain after 1000 years.
