Question 1

Which scientist is credited with predicting the properties of missing elements and organizing the periodic table based on both atomic mass and chemical properties?

Accepted Answer

Dmitri Mendeleev

Question 2

What is the formula for effective nuclear charge ($$Z_{	ext{eff}}) $$experienced by a valence electron?

Accepted Answer

$$Z_{	ext{eff}} = Z - S$$

Question 3

Which property generally increases from left to right across a period and decreases from top to bottom within a group?

Accepted Answer

Ionization energy

Question 4

Why are cations smaller than their parent atoms?

Accepted Answer

Cations lose their outermost electron(s), reducing electron repulsion.

Question 5

In an isoelectronic series, what happens to ionic radius as nuclear charge increases?

Accepted Answer

Ionic radius decreases.

Question 6

Which group of elements is characterized by very large ionization energies, positive electron affinities, and being monatomic gases?

Accepted Answer

Group 8A: Noble gases

Question 7

A student is asked to explain why sodium reacts with oxygen to form a peroxide, while potassium forms a superoxide. Which concept best explains this difference?

Accepted Answer

Increasing ionic radius and stabilization of larger anions

Question 8

Which property is NOT typical of metals?

Accepted Answer

High ionization energies

Question 9

Which of the following statements about electron affinity is correct?

Accepted Answer

Electron affinity is typically exothermic, but can be positive for some elements.

Question 10

A chemist observes that magnesium reacts only with steam, while calcium reacts readily with water. What trend does this illustrate?

Accepted Answer

Increasing reactivity down Group 2A due to electrons being further from the nucleus

Question 11

Which element is a metalloid and is commonly used as a semiconductor in computer chips?

Accepted Answer

Silicon

Question 12

What is the main reason for the periodicity observed in the properties of elements?

Accepted Answer

The repetitive pattern based on atomic number

Question 13

Which of the following best describes the trend in bonding atomic radius across a period?

Accepted Answer

Bonding atomic radius decreases from left to right.

Question 14

Which group of elements is most likely to form anions due to their large negative electron affinity?

Accepted Answer

Nonmetals

Question 15

A sample of neon, sodium ion ($$	ext{Na}^+$$), and fluoride ion ($$	ext{F}^-) $$all have 10 electrons. Which has the smallest ionic radius?

Accepted Answer

$$	ext{Na}^+$$

Question 16

Which property is characteristic of most nonmetal oxides?

Accepted Answer

They are acidic.

Question 17

Which element in Group 6A is most likely to have a positive charge?

Accepted Answer

Polonium

Question 18

Which of the following statements about alkali metals is correct?

Accepted Answer

They have low densities and melting points.

Question 19

Which property explains why noble gases are relatively unreactive?

Accepted Answer

They have full electron shells and very large ionization energies.

Question 20

Which of the following best describes the electron configuration of hydrogen?

Accepted Answer

It suggests hydrogen should be a metal, but it behaves as a nonmetal.

Periodic Properties of the Elements: Structured Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard