will be largest for 
.
Explanation: Ionization energy is the energy to knock off an electron from a gaseous atom of ion. First ionization energy or is the energy required to remove 1 loosely held electron from 1 mole of gaseous atoms to produce 1 mole of gaseous ion carrying (+)1 charge.
The electrons are filled according to Aufbau's rule and the orbitals which are strongly held to the nucleus follows the order 
.
Electron is released from the outermost shell that is from the electrons which are loosely held to the nucleus, this follows the pattern 
.
In configurations, 
The loosely held orbital is 4s, therefore electron will be lost from that easily.
Now, in 3p orbital, one configuration has 5 electrons and one has 1 electron.
The configuration having 5 electrons will be more tightly held by the nucleus because it has more electrons that the one having only 1 electron. Hence, the electron will be lost easily from the configuration having 
as the valence shell.
Therefore, the configuration will the largest .
Generally speaking the larger, more massive elements are less stable, like isotopes of elements. With this said, they are less likely to react since they will become heavy and unstable. This is why chlorine is more reactive with other elements like sodium than astatine.
Answer:
what is late ? there is no attachment ?
"Like dissolves like" is an expression used by chemists to remember how some solvents work. It refers to "polar" and "non-polar" solvents and solutes. Basic example: Water is polar. Oil is non polar. Like dissolves like, that means polar dissolves polar, so water dissolves salt.
Atoms are the simpliest form of matter. But an atom can
be classified as an element and an element can be presented various substance. An
element can be oxygen, hydrogen and so on. The combination of two or more
elements is a compound. A compound can be a molecule, same as the atom to
element.
