Question 1

Which scientist is credited with organizing the periodic table based on atomic mass and predicting the existence and properties of undiscovered elements?

Accepted Answer

Dmitri Mendeleev

Question 2

What is the most fundamental property used to organize the modern periodic table?

Accepted Answer

Atomic number

Question 3

Which of the following best describes periodicity in the context of the periodic table?

Accepted Answer

The repetitive pattern of a property as a function of atomic number

Question 4

According to Coulomb's Law, what happens to the force between two charges if the distance between them is halved?

Accepted Answer

The force is quadrupled

Question 5

Which equation correctly represents Coulomb's Law for the force between two charges?

Accepted Answer

$$F_\mathrm{coulomb} = k \frac{Q_1$ Q_2$}{d^2$}$$

Question 6

What is the effect of electron shielding in a many-electron atom?

Accepted Answer

It cancels out some of the attractive force from the nucleus, reducing the effective nuclear charge

Question 7

Which trend is observed for atomic radius as you move across a period from left to right?

Accepted Answer

Atomic radius decreases

Question 8

What happens to the atomic radius as you move down a group in the periodic table?

Accepted Answer

Atomic radius increases

Question 9

Which of the following ions has the smallest ionic radius: $$\mathrm{Na^+}$$, $$\mathrm{Mg$$^{2+}$$}$$, $$\mathrm{Al$$^{3+}$$}$$, or $$\mathrm{F^-}$$?

Accepted Answer

$$\mathrm{Al$$^{3+}$$}$$

Question 10

Which statement about ionization energy is correct?

Accepted Answer

Ionization energy generally increases across a period

Question 11

Why is the second ionization energy of sodium much higher than the first?

Accepted Answer

The second electron is a core electron, which is much closer to the nucleus

Question 12

Which of the following elements has the highest first ionization energy?

Accepted Answer

Chlorine ($$\mathrm{Cl})$$

Question 13

What is electron affinity?

Accepted Answer

The energy change when an electron is added to a gaseous atom

Question 14

Which group in the periodic table generally has the most negative electron affinity values?

Accepted Answer

Group 7A (halogens)

Question 15

Why do noble gases have electron affinity values close to zero or positive?

Accepted Answer

Their valence shells are already full, so adding an electron is energetically unfavorable

Question 16

Which factor does NOT affect the size of an ion?

Accepted Answer

The number of neutrons

Question 17

If an atom forms a cation, what happens to its radius compared to the neutral atom?

Accepted Answer

The radius decreases

Question 18

Which of the following best explains the trend in effective nuclear charge ($$Z_{\mathrm{eff}}) $$across a period?

Accepted Answer

$$Z_{\mathrm{eff}}$$ increases because the number of protons increases while shielding remains relatively constant

Question 19

Which of the following ions are isoelectronic (have the same number of electrons)?

Accepted Answer

$$\mathrm{Na^+}$$, $$\mathrm{Mg$$^{2+}$$}$$, $$\mathrm{Al$$^{3+}$$}$$, $$\mathrm{F^-}$$

Question 20

A hospital is using argon gas in a medical device. Why is argon unlikely to form an anion ($$\mathrm{Ar^-}) $$under normal conditions?

Accepted Answer

Argon has a full valence shell, so adding an electron is energetically unfavorable

Chapter 7: Periodic Properties of the Elements – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard