Answer:
If you are given with the atomic number of an element you can find it's period number and group number. The period number is related to the number of electron occupied shells in the element and the period number is linked to its valence electrons.
Explanation:
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The halogens and noble gases are alike because they are all non-metallic elements, with the exception of astatine, a radioactive
Answer:
The volume of the solution is 0.305 liters.
Explanation:
Molar mass is the amount of mass that a substance contains in one mole. The molar mass of K₂Cr₂O₇ is 294 g / mole. Then you can apply the following rule of three: if by definition of molar mass 294 grams of the compound are contained in 1 mole, 180 grams are contained in how many moles?

moles= 0.61
Molarity is a measure of the concentration of a substance that is defined as the number of moles contained in a certain volume. So, the molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:

Molarity is expressed in units
.
In this case:
- molarity= 2 M
- number of moles of solute= 0.61 moles
- volume= ?
Replacing in the definition of molarity:

Solving:

volume= 0.305 liters
<u><em>The volume of the solution is 0.305 liters.</em></u>
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.
There are 0.000076 moles in 4.6 x 10^19 atoms.