Answer: Elements in Group 2
Explanation: The periodic table was arranged by Dmitri Mendeleev specifically around similarites in their chemical behaviors. He found that as atomic number increases, at some point an element starts to react in a manner similar to a previous one. When that happened, he would place the larger element under the smaller one, and eventually noticed a periodicity in the table. Elements in a column (Groups) had similiar chemical properties. We know today that these similarities are due to the electron configuration, and that these configurations repeat themselves. He left gaps in the table when he could find an existing element with properties similar to others in that group. I big leap of faith, but it worked. Elements for those missing boxes were eventually discovered.
Answer:
The internal energy is the total amount of kinetic energy and potential energy of all the particles in the system. ... When the substance melts or boils, energy is put in to breaking the bonds that are holding particles together, which increases the potential energy.
Explanation:
There are 0.109 moles of NaCl in one tablespoon of salt. This is found by dividing the number of grams you have by the molecular weight.