Question

question 39 (1 point)
what is the energy required to remove an electron from an atom in the gaseous state called?
ionization energy
electronegative energy
shielding energy
nuclear energy

question 40 (1 point)
by the early 1800s, chemists started organizing elements into groups because
there were so many new elements that had been discovered.
more books were being published on the topic.
universities had a sudden influx of students interested in chemistry.
the printing press made it possible to disseminate knowledge faster.

question 41 (1 point)
which of the following factors contributes to the decrease in ionization energy within a group in the periodic table as the atomic number increases?
fewer electrons in the highest occupied energy level
increase in number of protons
increase in size of the nucleus
increase in atomic size

Explanation:

Question 39

Ionization energy is defined as the energy required to remove an electron from an atom in the gaseous state. Electronegative energy is not a standard term in this context. Shielding energy refers to the reduction in attraction between electrons and the nucleus due to inner - shell electrons. Nuclear energy is related to energy from nuclear reactions.

By the early 1800s, many new elements were discovered. Chemists started organizing elements into groups to better understand and classify these numerous elements. The publication of more books (option b) and the influx of students (option c) are not the main reasons for organizing elements. The printing press (option d) is a general factor for knowledge dissemination but not the specific reason for element organization.

As the atomic number increases within a group in the periodic table, the atomic size increases. Larger atoms have their outermost electrons farther from the nucleus, and the attraction between the nucleus and the outermost electrons is weaker. So, less energy (ionization energy) is required to remove an electron. Fewer electrons in the highest occupied energy level (option a) is not a factor as the number of valence electrons is the same within a group. Increase in the number of protons (option b) and increase in the size of the nucleus (option c) would, if not for the increase in atomic size, tend to increase ionization energy due to stronger nuclear charge.

Answer:

A. ionization energy

Question 40