BackClose

Select a Subject

Subject Test Chemistry

Question 6 of 9

beginning of content:
Tags:
SAT Subject Test

Each of the following questions consists of two statements, I in the left-hand column and II in the right-hand column. For each question, determine whether statement I is true or false and whether statement II is true or false. Select the appropriate answer combination from the choices below. Choices with a filled CE oval denote that statement II is a correct explanation of the true statement I.

Potassium has a lower first ionization energy than lithium has
BECAUSE
potassium has more protons in its nucleus than lithium has.

Select an Answer

The figure shows a sample answer grid for question number one hundred one. Option (A) shows the sample answer grid that has a true and a false bubble option for the Roman numeral I statement, a true and false bubble option for the Roman numeral II statement, and a single bubble option for C E. For the Roman numeral I statement the true bubble is filled in, for the Roman numeral II statement the true bubble is filled in, and the C E bubble is filled in.

Correct Answer: 
No

The figure shows a sample answer grid for question number one hundred one. Option (B) shows the sample answer grid that has a true and false bubble option for the Roman numeral I statement, a true and false bubble option for the Roman numeral II statement, and a single bubble option for C E. For the Roman numeral I statement the true bubble is filled in, for the Roman numeral II statement the true bubble is filled in, and the C E bubble is NOT filled in.

Correct Answer: 
Yes

The figure shows a sample answer grid for question number one hundred one. Option (C) shows the sample answer grid that has a true and false bubble option for the Roman numeral I statement, a true and false bubble option for the Roman numeral II statement, and a single bubble option for C E. For the Roman numeral I statement the true bubble is filled in, for the Roman numeral II statement the false bubble is filled in, and the C E bubble is NOT filled in.

Correct Answer: 
No

The figure shows a sample answer grid for question number one hundred one. Option (D) shows the sample answer grid that has a true and false bubble option for the Roman numeral I statement, a true and false bubble option for the Roman numeral II statement, and a single bubble option for C E. For the Roman numeral I statement the false bubble is filled in, for the Roman numeral II statement the true bubble is filled in, and the C E bubble is NOT filled in.

Correct Answer: 
No

The figure shows a sample answer grid for question number one hundred one. Option (E) shows the sample answer grid that has a true and false bubble option for the Roman numeral I statement, a true and false bubble option for the Roman numeral II statement, and a single bubble option for C E. For the Roman numeral I statement the false bubble is filled in, for the Roman numeral II statement the false bubble is filled in, and the C E bubble is NOT filled in.

Correct Answer: 
No

Ionization energy depends on effective nuclear charge and the distance of the electron from the nucleus. Outer electrons are partially shielded from the nucleus by inner electrons, so the effective nuclear charge is about the same for atoms of elements in the same group of the periodic table. Potassium left parenthesis text K end text right parenthesis and lithium left parenthesis text Li end text right parenthesis are in the same group of the periodic table, but the lithium atom has fewer occupied shells and a smaller atomic radius. The outermost electron in text Li end text is in a shell that is close to the nucleus, and the outermost electron in text K end text is in a shell that is relatively far from the nucleus. Therefore, there is less attraction between the outermost electron in a text K end text atom and its nucleus than between the outermost electron in a text Li end text atom and its nucleus, and it is easier to remove an electron from a text K end text atom, resulting in a lower first ionization energy for text K end text than for text Li end text. It is true that text K end text (atomic
number 19) has more protons in its nucleus than does text Li end text (atomic number 3), but this is not the reason for the relative ionization energies. (Note, for example, that text Ca end text has more protons in its nucleus than does text K end text, but text Ca end text has a higher first ionization energy than does text K end text.) The correct answer is true, true, not a correct explanation.

Question Difficulty: 
medium