Describe the trends in first ionization energy within groups and across periods in the periodic table. provide examples.

The trend  of first ionization  energy within  groups  and across  the  periods  in periodic table   is that

 Within the group

 The   first ionization  energy  decrease from the top  to the bottom   within a  group.

-For  example in  group 1  ionization  energy for of rubidium is less  than that  of lithium.

Across  the period.

 The first  ionization  energy  increases across the period,  that is from   the  left  to  the  right.  

-  for example  in period   2    ionization  energy   for lithium    is   less than that  fluorine.

Ionization energy is the energy that is vital in removing an electron from a neutral atom in its gaseous stage. The elements on the right side of the periodic table have a higher ionization energy in general because their valence shell is almost full. On the other hand, the elements on the left side of the periodic table have low ionization energies due to their eagerness to lose electrons and will turn out to be cations. That being the case, ionization energy increases from left to right on the periodic table. There are some elements that have a few ionization energies and these different energies are described as the first ionization energy, the second ionization energy, third ionization energy, etc. The first one is the energy that is obliged to take away the outermost, or highest, energy electron, on the other hand, the second one is the energy that is required to take away any succeeding high-energy electron from a gaseous cation, etc. Furthermore, any subsequent ionization energies basically follow the same periodic trend in the same way as the first ionization energy. Additionally, ionization energies decrease when atomic radii increase.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.